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277

Chapter 7  Tutorial

Measurement Fundamentals

4

7

Sources of Error in DC Voltage Measurements 

Common Mode Rejection   

Ideally, the internal DMM is completely 

isolated from earth-referenced circuits. However, there is finite 
resistance and capacitance between the input LO terminal and earth 
ground. If the input terminals are both driven by an earth-referenced 
signal (V

f

) then a current will flow through R

S

 and create a voltage drop 

V

L

 as shown below. 

Any resulting voltage (V

L

) will appear as an input to the internal DMM. 

As the value of R

S

 approaches zero, so does the error. Additionally, if V

f

 

is at the power line frequency (50 Hz or 60 Hz), the noise can be greatly 
reduced by setting the internal DMM’s integration time to 1 PLC 
or greater (

see page 120 for a discussion of integration time)

. 

Where: 

V

f

 = Common mode float voltage 

R

s

 = LO lead resistance 

R

i

 = Isolation resistance 

C

i

 = Isolation capacitance 

Z

i

 = Parallel impedance of R

i

 + C

i

 

Error (V

L

) =

 

DMM

R

i

>10 G

C

i

250 pF

HI

V

test

V

f

R

s

LO

+ V

L

 -

Vf Rs

Rs Z

+

-------------------

34970A Refresh UG.book  Page 277  Wednesday, February 17, 2010  12:34 PM

Содержание 34970A

Страница 1: ...Agilent Technologies Agilent 34970A 34972A Data Acquisition Switch Unit User s Guide cover fm Page 1 Thursday December 10 2009 5 38 PM ...

Страница 2: ...rmity You can then search by product number to find the latest Decla ration of Conformity Warranty The material contained in this document is provided as is and is subject to being changed with out notice in future editions Further to the maximum extent permitted by applicable law Agi lent disclaims all warranties either express or implied with regard to this manual and any information contained h...

Страница 3: ...s Before Applying Power Verify that all safety precautions are taken Make all connections to the unit before applying power and select the appropriate power line voltage on the fuse module Ground the Instrument This product is provided with protec tive earth terminals To minimize shock hazard the instrument must be con nected to the ac power mains through a grounded power cable with the ground wir...

Страница 4: ...o contact your Agilent Technologies Representative Safety Symbols Alternating current Frame or chassis terminal Standby supply Unit is not completely disconnected from AC mains when switch is off Caution risk of electric shock Caution refer to accompanying documents Earth ground terminal CAT I IEC Measurement 1SM1 The CE mark is a registered trademark of the European The CSA mark is a registered t...

Страница 5: ...dent channel configuration with function Mx B scaling and alarm limits available on a per channel basis Intuitive user interface with knob for quick channel selection menu navigation and data entry from the front panel Portable ruggedized case with non skid feet BenchLink Data Logger 3 Software for Microsoft Windows included Flexible Data Acquisition Switching Features 6 digit multimeter accuracy ...

Страница 6: ... Scaling Configuration Menu 5 Alarm Alarm Output Configuration Menu 6 Scan to Scan Interval Menu 7 Scan List Single Step Read Key 8 Advanced Measurement Utility Menus 9 Low Level Module Control Keys 10 Single Channel Monitor On Off Key 11 View Scanned Data Alarms Errors Menu 12 Shift Local Key 13 Knob 14 Navigation Arrow Keys 34970A Refresh UG book Page 6 Wednesday February 17 2010 12 34 PM ...

Страница 7: ... 2 Press the same menu key again to move to the next item of the menu Typically this is where you choose parameter values for the selected operation 3 Rotate the knob to view the choices on this level of the menu When you reach the end of the list rotate the knob in the opposite direction to view all of the other choices The current selection is highlighted for emphasis All other choices are dimme...

Страница 8: ...verflow new readings will overwrite the oldest readings A USB drive is connected to the instrument annunciator on or data is being written to or read from the USB drive annunciator flashing AUTO 34972A USB logging is active LAST Viewed data is the last reading stored during most recent scan MIN Viewed data is the minimum reading stored during most recent scan MAX Viewed data is the maximum reading...

Страница 9: ...xt Trig Input Alarm Outputs Channel Advance Input Channel Closed Output for pinouts see pages 99 and 145 3 RS 232 Interface Connector 4 Power Line Fuse Holder Assembly 5 Power Line Voltage Setting 6 Chassis Ground Screw 7 GPIB IEEE 488 Interface Connector Use the Menu to Select the GPIB or RS 232 interface see chapter 2 Set the GPIB address see chapter 2 Set the RS 232 baud rate parity and flow co...

Страница 10: ...t Trig Input Alarm Outputs Channel Advance Input Channel Closed Output for pinouts see pages 99 and 145 4 Power Line Fuse Holder Assembly 5 LAN Connector 6 USB Drive Connector 7 USB Interface Connector Use the Menu to Select and configure the LAN and USB interfaces see chapter 2 Device LAN ExtT rig Alarms 5V Line 50 60 400 Hz Fuse 500m AT 250V Opt 001 LXI Class C Host 30 VA Max N10149 ICES NM B 00...

Страница 11: ...ta export A data log name template Automatic data export with preconfigured preferences control of the decimal character and field separator control of the export contents Graph configurations saved and restored automatically the next time Data Logger 3 is opened Graph preferences to allow easy control of graph look and feel Split graphs for easy viewing of independent measurements Import Data Log...

Страница 12: ...rnal shunt resistors are not required You can close multiple channels on this module only if you have not configured any channels to be part of the scan list Otherwise all channels on the module are break before make 34902A 16 Channel Reed Multiplexer 16 channels of 300 V switching Built in thermocouple reference junction Switching speed of up to 250 channels per second Connects to the internal mu...

Страница 13: ...an be connected at a time 300 V 1 A switching For detailed information and a module diagram see page 207 Use this module to connect multiple instruments to multiple points on your device under test at the same time You can connect rows and columns between multiple modules to build larger matrices such as 8x8 and 4x16 with up to 96 crosspoints in a single mainframe 34905 6A Dual 4 Channel RF Multip...

Страница 14: ...d digital inputs and the count on the totalizer during a scan 34908A 40 Channel Single Ended Multiplexer 40 channels of 300 V single ended common LO switching Built in thermocouple reference junction Switching speed of up to 60 channels per second Connects to the internal multimeter For detailed information and a module diagram see page 213 Use this module for high density switching applications w...

Страница 15: ...s that may appear as you are working with the instrument Each listing contains enough information to help you diagnose and solve the problem Application Programs Chapter 6 contains several remote interface program examples to help you develop programs for your application Tutorial Chapter 7 discusses measurement considerations and techniques to help you obtain the best accuracies and reduce source...

Страница 16: ...16 34970A Refresh UG book Page 16 Wednesday February 17 2010 12 34 PM ...

Страница 17: ...w Front Panel Menu Reference 41 To Monitor a Single Channel 44 To Set a Scan Interval 45 To Apply Mx B Scaling to Measurements 46 To Configure Alarm Limits 47 To Read a Digital Input Port 49 To Write to a Digital Output Port 50 To Read the Totalizer Count 51 To Output a DC Voltage 52 To Configure the Remote Interface 34970A 53 To Configure the Remote Interface 34972A 55 To Store the Instrument Sta...

Страница 18: ...C Output Operations 159 System Related Operations 160 Single Channel Monitoring 171 Mass Memory USB Subsystem 34972A 174 USB Drive Front Panel 34972A 181 Remote Interface Configuration 34970A 183 Remote Interface Configuration 34972A 188 Calibration Overview 192 Factory Reset State 197 Instrument Preset State 198 Multiplexer Module Default Settings 199 Module Overview 200 34901A 20 Channel Multipl...

Страница 19: ...e 314 Relay Life and Preventive Maintenance 321 Chapter 8 Specifications DC Resistance and Temperature Accuracy Specifications 326 DC Measurement and Operating Characteristics 327 AC Accuracy Specifications 328 AC Measurement and Operating Characteristics 329 System Characteristics 330 System Speed Specifications 1 331 System Speed Specifications 332 Module Specifications 333 Module Specifications...

Страница 20: ...34970A Refresh UG book Page 20 Wednesday February 17 2010 12 34 PM ...

Страница 21: ...1 1 Quick Start 34970A Refresh UG book Page 21 Wednesday February 17 2010 12 34 PM ...

Страница 22: ... key that has the desired label below it For example to select the Utility Menu press If you accidentally press just press it again to turn off the SHIFT annunciator This chapter is divided into the following sections To Prepare the Instrument for Use on page 23 BenchLink Data Logger Software on page 25 To Connect Wiring to a Module on page 27 To Set the Time and Date on page 29 To Configure a Cha...

Страница 23: ...ipping container 2 Verify that the fuse on the back is set to the proper voltage range for your AC power 3 Connect the power cord and turn on the instrument The front panel display will light up briefly while the instrument performs its power on self test The instrument initially powers up with all measurement channels turned off To review the power on display with all annunciators turned on hold ...

Страница 24: ...ormed at power on Hold down as you turn on the instrument and hold down the key until you hear a long beep The self test will begin when you release the key following the beep If the self test fails see the 34970A 34972A Service Guide for instructions on returning the instrument to Agilent for service 34970A Refresh UG book Page 24 Wednesday February 17 2010 12 34 PM ...

Страница 25: ...with no programming required For system requirements and additional details on the features of the software refer to the specifications in chapter 8 BenchLink Data Logger 3 Software Installation Procedure Microsoft Windows Vista XP 2000 1 Insert the 34825A Product CD ROM into your drive 2 From the Product CD ROM window that is displayed locate Agilent BenchLink Data Logger 3 Software in the Softwa...

Страница 26: ...e Help system to help you learn the features of the software as well as troubleshoot any problems that might arise as you are using the software As you are installing the software you will notice that the on line Help system is available in several languages 34970A Refresh UG book Page 26 Wednesday February 17 2010 12 34 PM ...

Страница 27: ... mainframe Cable Tie Wrap optional For detailed information on each module refer to the section starting on page 200 To reduce wear on the internal DMM relays wire like functions on adjacent channels For information on grounding and shielding see page 259 The diagrams on page 28 show how to connect wiring to a multiplexer module for each measurement function 4 Replace the module cover Wiring Hints...

Страница 28: ...tor Types 2 2 k 5 k 10 k DC Current AC Current Valid only on channels 21 and 22 on the 34901A Ranges 10 mA 100 mA 1A Channel n source is automatically paired with Channel n 10 sense on the 34901A or Channel n 8 sense on the 34902A Ranges 100 1 k 10 k 100 k 1 M 10 M 100 M RTD Types 0 00385 0 00391 DC Voltage AC Voltage Frequency Ranges 100 mV 1 V 10 V 100 V 300 V 4 Wire Ohms RTD 34970A Refresh UG b...

Страница 29: ...m data is time stamped and stored in a separate non volatile memory queue 1 Set the time of day Use and to select the field to modify and turn the knob to change the value You can also edit the AM PM field 2 Set the date Use and to select the field to modify and turn the knob to change the value TIME 03 45 PM JUN 01 2009 34970A Refresh UG book Page 29 Wednesday February 17 2010 12 34 PM ...

Страница 30: ...plexer installed in slot 100 and select channel 103 2 Select the measurement parameters for the selected channel Use the knob to scroll through the measurement choices on each level of the menu When you press to make your selection the menu automatically guides you through all relevant choices to configure a measurement on the selected function When you have finished configuring the parameters you...

Страница 31: ...are automatically time stamped and stored in non volatile memory During the scan the instrument calculates and stores the minimum maximum and average on all channels in the scan list You can read the contents of memory at any time even during a scan From the front panel data is available for the last 100 readings on each channel readings taken during a scan all of the data is available from the re...

Страница 32: ...t the channel to copy the configuration from Turn the knob until the desired channel is shown on the right side of front panel display For this example let s copy the configuration from channel 103 2 Select the copy function Use the knob to scroll through the measurement choices until you see COPY CONFIG When you press to make your selection the menu automatically guides you to the next step 3 Sel...

Страница 33: ...n the selected channel Note will sequentially open all channels on the module in the selected slot The table below shows the low level control operations available for each of the plug in modules 1 Only one channel can be closed at a time on this module 2 Only one channel in each bank can be closed at a time on this module Plug In Module 34901A 20 Channel Mux 34902A 16 Channel Mux 34908A 40 Channe...

Страница 34: ...of the front panel 2 Verify that there is a battery in the instrument A battery must be present for the instrument to boot up 3 Verify the power line voltage setting The line voltage is set to the proper value for your country when the instrument is shipped from the factory Change the voltage setting if it is not correct The settings are 100 120 220 or 240 VAC Note For 127 VAC operation use the 12...

Страница 35: ...sembly in the rear panel Fuse 500 mAT for all line voltages Agilent Part Number 2110 0458 3 Rotate the line voltage selector until the correct voltage appears in the window 1 Remove the power cord Remove the fuse holder assembly from the rear panel 100 120 127 220 230 or 240 VAC 34970A Refresh UG book Page 35 Wednesday February 17 2010 12 34 PM ...

Страница 36: ...o Adjust the Carrying Handle To adjust the position grasp the handle by the sides and pull outward Then rotate the handle to the desired position Bench top viewing position Carrying position 34970A Refresh UG book Page 36 Wednesday February 17 2010 12 34 PM ...

Страница 37: ...ck mounting kit Any Agilent System II instrument of the same size can be rack mounted beside the 34970A 34972A Note Remove the carrying handle and the front and rear rubber bumpers before rack mounting the instrument To remove the handle rotate it to the vertical position and pull the ends outward Front Rear bottom view To remove the rubber bumper stretch a corner and then slide it off 34970A Refr...

Страница 38: ... by side order lock link kit 5061 9694 and flange kit 5063 9212 Be sure to use the support rails inside the rack cabinet To install one or two instruments in a sliding support shelf order shelf 5063 9255 and slide kit 1494 0015 for a single instrument also order filler panel 5002 3999 34970A Refresh UG book Page 38 Wednesday February 17 2010 12 34 PM ...

Страница 39: ...2 2 Front Panel Overview 34970A Refresh UG book Page 39 Wednesday February 17 2010 12 34 PM ...

Страница 40: ...is chapter is divided into the following sections Front Panel Menu Reference on page 41 To Monitor a Single Channel on page 44 To Set a Scan Interval on page 45 To Apply Mx B Scaling to Measurements on page 46 To Configure Alarm Limits on page 47 To Read a Digital Input Port on page 49 To Write to a Digital Output Port on page 50 To Read the Totalizer Count on page 51 To Output a DC Voltage on pag...

Страница 41: ...solution Copy and paste measurement configuration to other channels Configure the scaling parameters for the displayed channel Set the gain M and offset B value for the displayed channel Make a null measurement and store it as the offset value Specify a custom label RPM PSI etc for the displayed channel Configure alarms on the displayed channel Select one of four alarms to report alarm conditions ...

Страница 42: ... digital operations digital input output only Configure the totalizer reset mode totalizer only Select which edge is detected rising or falling for totalizer operations Configure system related instrument parameters Set the real time system clock and calendar Query the firmware revisions for the mainframe and installed modules Select the instrument s power on configuration last or factory reset En...

Страница 43: ... down state factory reset state or preset state Configure the remote interface 34970A Select the GPIB address Configure the RS 232 interface baud rate parity and flow control Configure the remote interface 34972A Configure the LAN settings IP Address Hostname DHCP etc Configure the USB settings Enable USB ID etc Configure and use the USB drive Logging etc 34970A Refresh UG book Page 43 Wednesday F...

Страница 44: ... monitored at a time but you can change the channel being monitored at any time by turning the knob 2 Enable monitoring on the selected channel Any channel that can be read by the instrument can be monitored the MON annunciator turns on This includes any combination of temperature voltage resistance current frequency or period measurements on multiplexer channels You can also monitor a digital inp...

Страница 45: ...mode For this example select the Interval Scan mode which allows you to set the time from the start of one scan sweep to the start of the next scan sweep Set the interval to any value between 0 and 99 hours 2 Select the scan count You can specify the number of times that the instrument will sweep through the scan list the default is continuous When the specified number of sweeps have occurred the ...

Страница 46: ...rned off on that channel and the gain and offset values are reset M 1 and B 0 2 Set the gain and offset values The scaling values are stored in non volatile memory for the specified channels A Factory Reset turns off scaling and clears the scaling values on all channels An Instrument Preset or Card Reset does not clear the scaling values and does not turn off scaling 3 Select the custom label You ...

Страница 47: ...st configure the channel function transducer type etc before setting any alarm limits If you change the measurement configuration alarms are turned off and the limit values are cleared If you plan to use Mx B scaling on a channel which will also use alarms be sure to configure the scaling values first 2 Select which of the four alarms you want to use 3 Select the alarm mode on the selected channel...

Страница 48: ...ts and does not turn off alarms 5 Run the scan and store the readings in memory If an alarm occurs on a channel as it is being scanned then that channel s alarm status is stored in reading memory as the readings are taken Each time you start a new scan the instrument clears all readings including alarm data stored in reading memory from the previous scan As alarms are generated they are also logge...

Страница 49: ... the knob until DIN is displayed channel 01 or 02 2 Read the specified port You can specify whether you want to use binary or decimal format Once you have selected the number base it is used for all input or output operations on the same port To change the number base press the key and select USE BINARY or USE DECIMAL The bit pattern read from the port will be displayed until you press another key...

Страница 50: ...an output port DOUT 3 Edit the bit pattern Use the knob and or keys to edit the individual bit values You can specify whether you want to use binary or decimal format Once you have selected the number base it is used for all input or output operations on the same port To change the number base press the key and select USE BINARY or USE DECIMAL 4 Output the bit pattern to the specified port The spe...

Страница 51: ...s as soon as you turn on the instrument You can configure the totalizer to reset the count to 0 after being read or it can count continuously and be manually reset 3 Read the count The count is read once each time you press the count does not update automatically on the display As configured in this example the count is automatically reset to 0 each time you read it The count will be displayed unt...

Страница 52: ... module and continue turning the knob until DAC is displayed channel 04 or 05 2 Enter the output voltage editor 3 Set the desired output voltage Use the knob and or keys to edit the individual digits 4 Output the voltage from the selected DAC The output voltage will be displayed until you press another key or turn the knob To manually reset the output voltage to 0 volts press 00 000 V DAC 05 250VD...

Страница 53: ...om the factory 1 Select the GPIB interface 2 Select the GPIB address You can set the instrument s address to any value between 0 and 30 The factory setting is address 9 3 Save the change and exit the menu Note Your computer s GPIB interface card has its own address Be sure to avoid using the computer s address for any instrument on the interface bus Agilent s GPIB interface cards generally use add...

Страница 54: ...ect one of the following None 8 data bits factory setting Even 7 data bits or Odd 7 data bits When you set the parity you are also indirectly setting the number of data bits 4 Select the flow control method Select one of the following None no flow control RTS CTS DTR DSR XON XOFF factory setting or Modem 5 Save the changes and exit the menu RS 232 Configuration RS 232 19200 BAUD EVEN 7 BITS FLOW D...

Страница 55: ...ce and a Universal Serial Bus USB interface Both interfaces can be enabled at the same time and both interfaces are selected when the instrument is shipped from the factory 1 Select the LAN interface 2 Enable the LAN This is enabled by default 3 Configure the instrument LAN settings according the instructions provided by your LAN administrator LAN Configuration LAN INTERFACE LAN ENABLED ...

Страница 56: ...e USB ID String The instrument will display its USB identification USB ID string This is helpful in identifying the device on the USB network Use the left and right arrows above the knob to view the full string 4 Save the changes and exit the menu USB Configuration USB INTERFACE USB ENABLED USB0 2391 8199 MY01023529 0 INSTR 34970A Refresh UG book Page 56 Wednesday February 17 2010 12 34 PM ...

Страница 57: ... be resumed 1 Select the storage location From the front panel you have the ability to assign names up to 12 characters to each of the five stored states The storage locations are numbered 1 through 5 The power down state is automatically stored and can be recalled from the front panel the state is named LAST PWR DOWN 2 Store the instrument state The instrument stores all channel configurations al...

Страница 58: ...58 Chapter 2 Front Panel Overview To Store the Instrument State 34970A Refresh UG book Page 58 Wednesday February 17 2010 12 34 PM ...

Страница 59: ...3 3 System Overview 34970A Refresh UG book Page 59 Wednesday February 17 2010 12 34 PM ...

Страница 60: ...Input on page 74 Control Output on page 83 Data Acquisition System Overview You can use the Agilent 34970A 34972A as a stand alone instrument but there are many applications where you will want to take advantage of the built in PC connectivity features A typical data acquisition system is shown below Computer and Software Interface Cable 34970A 34972A Plug in Modules System Cabling Sensors and Eve...

Страница 61: ...isadvantages Advantages Disadvantages Often built into the computer no additional hardware is required Cable length is limited to 45 ft 15 m Speed faster data and command transfers Cable length is limited to 60 ft 20m Drivers usually included in the operating system Only one instrument or device can be connected per serial port Additional system flexibility multiple instruments can be connected to...

Страница 62: ...s 34972A s Web Interface Simply enter the IP address of your instrument in your browser s navigation bar to launch the Web Interface The remote control page of the Web Interface shown below allows you to monitor your instrument set up and initiate scans save data to the USB drive and much more For help simply click on the large question mark on the far left side of the screen 34970A Refresh UG boo...

Страница 63: ...s software to set up your test acquire and archive measurement data and perform real time display and analysis of your measurements The Agilent BenchLink Data Logger Pro option available at additional cost provides advanced data logging and decision making with no programming required Automated Testing with Multiple Instruments Agilent VEE TransEra HTBASIC for Windows National Instruments LabVIEW ...

Страница 64: ...ction to provide PC connectivity The 34970A is shipped with both an GPIB IEEE 488 interface and an RS 232 interface Only one interface can be enabled at a time The 34972A is shipped with Local Area Network LAN and Universal Serial Bus USB connectivity The earth referenced section also provides four hardware alarm outputs and external trigger lines You can use the alarm output lines to trigger exte...

Страница 65: ...on volatile memory Plug In Modules The 34970A 34972A offers a complete selection of plug in modules to give you high quality measurement switching and control capabilities The plug in modules communicate with the floating logic via the internal isolated digital bus The multiplexer modules also connect to the internal DMM via the internal analog bus Each module has its own microprocessor to offload...

Страница 66: ...function Module Digital Input Event Counting Signal Routing 34901A 20 Channel Mux with T C Compensation Multiplexing of signals to or from external instruments 34902A 16 Channel Reed Mux with T C Compensation 34908A 40_Channel Single Ended Mux with T C Compensation 34904A 4x8 Matrix Switch 32 Crossppoint Matrix switching 34905A Dual 4 Channel RF Mux 50 50 high frequency applications 2 GHz 34906A D...

Страница 67: ...Cabling and Connections starting on page 257 Cable Type Common Uses Comments Thermocouple Extension Wire Thermocouple measurements Available in specific thermocouple types Also available in a shielded cable for added noise immunity Twisted Pair Shielded Twisted Pair Measurement inputs voltage outputs switching counting Most common cable for low frequency measurement inputs Twisted pair reduces com...

Страница 68: ... converts it to a corresponding temperature in C F or K Measurement Typical Transducer Types Typical Transducer Output Temperature Thermocouple 0 mV to 80 mV RTD 2 wire or 4 wire resistance from 5 to 500 Thermistor 2 wire resistance from 10 to 1 M Pressure Solid State 10 VDC Flow Rotary Type Thermal Type 4 mA to 20 mA Strain Resistive Elements 4 wire resistance from 10 to 10 k Events Limit Switche...

Страница 69: ...s numbered 1 through 4 For example you can configure the instrument to generate an alarm on Alarm 1 when a limit is exceeded on any of channels 103 205 or 320 You can also assign alarms to channels on the multifunction module For example you can generate an alarm when a specific bit pattern or bit pattern change is detected on a digital input channel or when a specific count is reached on a totali...

Страница 70: ...g frequency and environment The 34970A 34972A Relay Maintenance System automatically counts the cycles of each relay in the instrument and stores the total count in non volatile memory on each switch module Use this feature to track relay failures and to predict system maintenance requirements For more information on using this feature refer to Relay Cycle Count on page 169 Switching Topologies Se...

Страница 71: ... see page 77 Multiplexers are available in several types One Wire Single Ended Multiplexers for common LO measurements For more information see page 301 Two Wire Multiplexers for floating measurements For more information see page 301 Four Wire Multiplexers for resistance and RTD measurements For more information see page 302 Very High Frequency VHF Multiplexers for switching frequencies up to 2 8...

Страница 72: ...nd columns For example a simple 3x3 matrix could be used to connect three sources to three test points as shown below Any one of the signal sources can be connected to any one of the test inputs Be aware that with a matrix it is possible to connect more than one source at the same time It is important to make sure that dangerous or unwanted conditions are not created by these connections Source 1 ...

Страница 73: ... also called single pole double throw You can use Form C switches to route signals but they are typically used to control external devices Channel Open NC Contact Connected Channel Closed NO Contact Connected NO Normally Open NC Normally Closed NO NC COM NO NC COM 34970A Refresh UG book Page 73 Wednesday February 17 2010 12 34 PM ...

Страница 74: ...stance current frequency or period measurements on multiplexer channels A scan can also include a read of a digital port or a read of the totalizer count on the multifunction module The Internal DMM A transducer or sensor converts a physical quantity being measured into an electrical signal which can be measured by the internal DMM To make these measurements the internal DMM incorporates the follo...

Страница 75: ...ning The internal DMM includes signal conditioning amplification or attenuation and a high resolution up to 22 bits analog to digital converter A simplified diagram of the internal DMM is shown below To From Earth Referenced Section Optical Isolators Amp Signal Conditioning Analog to Digital Converter Main Processor Analog Input Signal 34970A Refresh UG book Page 75 Wednesday February 17 2010 12 3...

Страница 76: ...e to use for each measurement based on the input signal For fastest scanning operation use manual ranging for each measurement some additional time is required for autoranging since the instrument has to make a range selection Analog to Digital Conversion ADC The ADC takes a prescaled DC voltage from the signal conditioning circuitry and converts it to digital data for output and display on the fr...

Страница 77: ...l with multiplexer channels to create a scan During a scan the instrument connects the DMM to the configured multiplexer channels one at a time and makes a measurement on each channel Before you can initiate a scan you must set up a scan list to include all desired multiplexer or digital channels Channels which are not in the scan list are skipped during the scan The instrument automatically scans...

Страница 78: ... delay between channels in the scan list You can manually control a scan by repeatedly pressing from the front panel You can start a scan by sending a software command from the remote interface You can start a scan when an external TTL trigger pulse is received You can start a scan when an alarm condition is logged on the channel being monitored Scan List 1 sweep Scan to Scan interval 0 to 99 59 5...

Страница 79: ... this configuration you can use the 34970A 34972A for signal routing or control applications If you install a multiplexer plug in module you can use the 34970A 34972A for scanning with an external instrument You can connect an external instrument such as a DMM to the multiplexer COM terminal H L H L Input Channels H L H L External DMM Common Terminals COM 34970A Refresh UG book Page 79 Wednesday F...

Страница 80: ...ol lines are provided When the 34970A 34972A and the external instrument are properly configured you can synchronize a scan sequence between the two Channel Closed OUT 34970A 34972A External DMM Ext Trig IN VM Complete OUT Ext Trig IN GND 34970A Refresh UG book Page 80 Wednesday February 17 2010 12 34 PM ...

Страница 81: ...igital Input The multifunction module has two non isolated 8 bit input output ports which you can use for reading digital patterns You can read the live status of the bits on the port or you can configure a scan to include a digital read Each port has a separate channel number on the module and contains 8 bits You can combine the two ports to read a 16 bit word 8 8 Bit 0 Bit 0 Bit 7 Bit 7 Port 1 L...

Страница 82: ...t You can configure the totalizer to count on the rising edge or falling edge of the input signal The maximum count is 67 108 863 226 1 The count rolls over to 0 after reaching the maximum allowed value You can configure the totalizer to read without affecting the count or reset the count to zero without losing any counts Channel 03 IN IN Gate 26 Bits Totalize Gate 34970A Refresh UG book Page 82 W...

Страница 83: ...system digital output and voltage DAC output The multifunction module also contains digital input and event totalizer capabilities which are described in more detail starting on page 81 Digital Output The multifunction module has two non isolated 8 bit input output ports which you can use to output digital patterns Each port has a separate channel number on the module and contains 8 bits You can c...

Страница 84: ...age source for analog input control of other devices A simplified diagram is shown below You can set the output voltage to any value between 12 VDC and 12 VDC in 1 mV steps Each DAC is earth referenced it cannot float Each DAC channel is capable of supplying 10 mA maximum current Note You must limit the output current to 40 mA total for all three slots six DAC channels DAC 1 DAC 2 16 16 Channel 04...

Страница 85: ...lated Form C SPDT switches Each channel can switch up to 300V DC or AC rms Each switch can also switch up to 1 A DC or AC rms up to 50 W maximum For example the maximum current that you can switch at 120 V is 0 45 A as shown below Channel Open NC Contact Connected Channel Closed NO Contact Connected NO Normally Open NC Normally Closed NO NC COM NO NC COM Voltage Current 34970A Refresh UG book Page...

Страница 86: ...hannels The actuator switches can also be used to control power devices When used with high power devices however it is critical that you provide protection to the switch from capacitive and inductive loads to ensure maximum relay life for more information on attenuators see the discussion on page 309 34970A Refresh UG book Page 86 Wednesday February 17 2010 12 34 PM ...

Страница 87: ...4 4 Features and Functions 34970A Refresh UG book Page 87 Wednesday February 17 2010 12 34 PM ...

Страница 88: ...9 Digital Input Operations on page 151 Totalizer Operations on page 153 Digital Output Operations on page 157 DAC Output Operations on page 159 System Related Operations on page 160 Single Channel Monitoring on page 171 Mass Memory USB Subsystem 34972A on page 174 USB Drive Front Panel 34972A on page 181 Remote Interface Configuration 34970A on page 183 Remote Interface Configuration 34972A on pag...

Страница 89: ...0 or 300 and cc is the channel number You can specify a single channel multiple channels or a range of channels as shown below The following command configures a scan list to include only channel 10 on the module in slot 300 ROUT SCAN 310 The following command configures a scan list to include multiple channels on the module in slot 200 The scan list now contains only channels 10 12 and 15 the sca...

Страница 90: ...907A Multifunction Module digital input and totalizer only 34908A 40 Channel Single Ended Multiplexer Automated scanning is not allowed with the actuator module the matrix module or the RF multiplexer modules In addition a scan cannot include a write to a digital port or a voltage output from a DAC channel However you can write your own program to manually create a scan to include these operations...

Страница 91: ...n Mx B scaling and alarm limits are applied to measurements during a scan and all data is stored in non volatile memory You can read the contents of reading memory or the alarm queue at any time even during a scan In the Monitor function the instrument takes readings as often as it can on a single channel even during a scan see Single Channel Monitoring on page 171 This feature is useful for troub...

Страница 92: ... If a scan includes a read of the totalizer multifunction module the count is reset each time it is read during the scan only when the totalizer reset mode is enabled TOTalize TYPE RRESet command or the Advanced menu for the totalizer If you install a module while a scan is running the instrument will cycle power and resume scanning If you remove a module while a scan is running the instrument wil...

Страница 93: ...m that partially completed sweep will be discarded a sweep is one pass through the scan list For example assume that your scan list includes four multiplexer channels and you want to sweep through the scan list three times see diagram A power failure occurs after the second reading in the third scan sweep The instrument will discard the last two of the 10 readings and will resume scanning at the b...

Страница 94: ...nfiguration also valid during a scan When you reconfigure a channel and add it to the scan list it is important to note that the previous configuration on that channel is lost For example assume that a channel is configured for DC voltage measurements When you reconfigure that channel for thermocouple measurements the previous range resolution and channel delay are set to their Factory Reset RST c...

Страница 95: ...ate command stores readings in memory Use the FETCh command to retrieve stored readings from memory See the Agilent 34970A 34972A Programmer s Reference Help for more information on using these commands When you reconfigure a channel and add it to the scan list using MEASure or CONFigure it is important to note that the previous configuration on that channel is lost For example assume that a chann...

Страница 96: ...rnal TTL trigger pulse is received You can start a scan when an alarm event is logged on the channel being monitored Interval Scanning In this configuration you control the frequency of scan sweeps by selecting a wait period from the start of one sweep to the start of the next sweep called the scan to scan interval The countdown time is shown on the front panel display between one scan sweep and t...

Страница 97: ...unt to continuous From the remote interface a Factory Reset RST command sets the scan interval to immediate 0 seconds and the scan count to 1 sweep Front Panel Operation To select interval scanning and set a scan interval time hour minutes seconds choose the following item INTERVAL SCAN To initiate the scan and store all readings in memory press the SCAN annunciator will turn on Between scan sweep...

Страница 98: ...tion and all data is stored in non volatile memory Front Panel Operation MANUAL SCAN To initiate the scan and store all readings in memory press The ONCE annunciator turns on as a reminder that a Scan Once operation is in progress Note To stop a scan press and hold Remote Interface Operation The following program segment configures the instrument for a Scan Once operation TRIG SOURCE BUS Select th...

Страница 99: ...ger before generating an error All readings from the scan are stored in non volatile memory Readings accumulate in memory until the scan is terminated until the scan count is reached or until you abort the scan Mx B scaling and alarm limits are applied to measurements during the scan and all data is stored in non volatile memory Front Panel Operation EXTERNAL SCAN To initiate the scan press The EX...

Страница 100: ...y use the Monitor function to continuously take readings on a selected channel and wait for an alarm on that channel The monitored channel can be part of the scan list but you can also use a channel on the multifunction module which does not have to be part of the scan list and you do not have to use the Monitor function For example you can generate an alarm on a totalizer channel which will initi...

Страница 101: ... The following program segment configures the instrument to scan when an alarm occurs TRIG SOURCE ALARM1 Select the alarm configuration TRIG COUNT 2 Sweep the scan list 2 times CALC LIM UPPER 5 103 Set the upper limit CALC LIM UPPER STATE ON 103 Enable the upper limit OUTPUT ALARM1 SOURCE 103 Report alarms on Alarm 1 ROUT MON 103 Select monitor channel ROUT MON STATE ON Enable monitoring INIT Init...

Страница 102: ... Scan see page 99 the scan count sets the number of external trigger pulses that will be accepted before terminating the scan During an Alarm Scan see page 100 the scan count sets the number of alarms that will be allowed before terminating the scan You can store up to 50 000 readings in non volatile memory during a scan If you set a continuous scan and memory overflows the MEM annunciator will tu...

Страница 103: ...efault is CONTINUOUS To set the count to a value between 1 and 50 000 scans turn the knob clockwise and enter a number Remote Interface Operation TRIG COUNT 20 Note To configure a continuous scan send TRIG COUNT INFINITY 34970A Refresh UG book Page 103 Wednesday February 17 2010 12 34 PM ...

Страница 104: ...ime time since start of scan Use the FORMat READ TIME TYPE command to select absolute or relative time From the front panel the time stamp is always returned in absolute time The MEASure and CONFigure commands automatically turn off the units time channel and alarm information A Factory Reset RST command turns off the units time channel and alarm information Remote Interface Operation The followin...

Страница 105: ...seconds and 60 seconds with 1 ms resolution You can select a different delay for each channel The default channel delay is automatic the instrument determines the delay based on function range integration time and AC filter setting see Automatic Channel Delays on the next page The MEASure and CONFigure commands set the channel delay to automatic A Factory Reset RST command also sets the channel de...

Страница 106: ...rmistor 2 and 4 wire Range Channel Delay For PLC 1 Range Channel Delay For PLC 100 1 k 10 k 100 k 1 M 10 M 100M 2 0 ms 2 0 ms 2 0 ms 25 ms 30 ms 200 ms 200 ms 100 1 k 10 k 100 k 1 M 10 M 100M 1 0 ms 1 0 ms 1 0 ms 20 ms 25 ms 200 ms 200 ms AC Voltage AC Current for all ranges AC Filter Channel Delay Slow 3 Hz Medium 20 Hz Fast 200 Hz 7 0 sec 1 0 sec 120 ms Frequency Period AC Filter Channel Delay S...

Страница 107: ...0 000 readings in non volatile memory during a scan From the front panel you can view the last 100 readings and all of the readings are available from the remote interface If memory overflows the MEM annunciator will turn on a status register bit is set and new readings will overwrite the first readings stored the most recent readings are always preserved Each time you start a new scan the instrum...

Страница 108: ...front panel all of the information is available for viewing For more information see Reading Format on page 104 Readings acquired during a Monitor are not stored in memory however all readings from a scan in progress at the same time are stored in memory The MEASure and READ commands send readings directly to the instrument s output buffer but readings are not stored in memory You will not be able...

Страница 109: ...and AVG annunciators turn on to indicate what data is currently being viewed Reading memory is not cleared when you read it Note that you can view readings from the front panel even while the instrument is in remote READINGS Select Channel Last Reading on Channel Time of Last Reading Minimum Reading on Channel Time of Minimum Reading Maximum Reading on Channel Time of Maximum Reading Average of Re...

Страница 110: ...on channel CALC AVER PTPEAK 305 Peak to peak maximum minimum The following command retrieves the last reading taken on channel 301 during a scan DATA LAST 301 The following command clears the contents of statistics memory for the selected channel CALC AVER CLEAR 305 Use the following command to determine the total number of readings stored in memory all channels from the most recent scan DATA POIN...

Страница 111: ...ernal DMM In this configuration you can use the 34970A 34972A for signal routing or control applications If you install a multiplexer plug in module you can use the 34970A 34972A for scanning with an external instrument You can connect an external instrument such as a DMM to the multiplexer COM terminal H L H L Input Channels H L H L External DMM Common Terminals COM 34970A Refresh UG book Page 11...

Страница 112: ...sable on page 167 Since the internal DMM is not used readings from multiplexer channels are not stored in internal reading memory External connections are required to synchronize the scan sequence between the 34970A 34972A and the external instrument The 34970A 34972A must notify the external instrument when a relay is closed and settled including channel delay The 34970A 34972A outputs a Channel ...

Страница 113: ...s have occurred the scan stops For more information refer to Scan Count on page 102 An externally controlled scan can also include a read of a digital port or a read of the totalizer count on the multifunction module When the channel advance reaches the first digital channel the instrument scans through all of the digital channels in that slot and stores the readings in reading memory only one cha...

Страница 114: ...G SOUR TIMER Select the scan interval ROUT CHAN ADV SOUR EXT Select the channel advance source TRIG TIMER 5 Set the scan interval to 5 seconds TRIG COUNT 2 Sweep the scan list 2 times INIT Initiate the scan To configure the instrument for 4 wire external scanning send the following command ROUTe CHANnel FWIRe OFF ON ch_list 34970A Refresh UG book Page 114 Wednesday February 17 2010 12 34 PM ...

Страница 115: ...ing Autoranging is convenient because the instrument decides which range to use for each measurement based on the input signal For fastest scanning operation use manual ranging on each measurement some additional time is required for autoranging since the instrument has to make a range selection Autorange thresholds Down range at 10 of range Up range at 120 of range If the input signal is greater ...

Страница 116: ... allows you to specify the range or autoranging The instrument returns to autoranging when the measurement function is changed and after a Factory Reset RST command An Instrument Preset SYSTem PRESet command or Card Reset SYSTem CPON command does not change the range setting Front Panel Operation First select the measurement function on the active channel You are automatically guided to the next l...

Страница 117: ...is is the 100 mVDC range 4 digits are displayed This is the 100 ohm range 6 digits are displayed For temperature measurements taken from the remote interface the resolution is fixed at 6 digits From the front panel you can set the resolution in terms of the number of digits displayed past the decimal point Measure menu For AC voltage measurements the resolution is fixed at 6 digits The only way to...

Страница 118: ...Integration Time on page 120 for more information The MEASure and CONFigure commands contain an optional resolution parameter which allows you to specify the resolution The instrument returns to 5 digits when the measurement function is changed and after a Factory Reset RST command An Instrument Preset SYSTem PRESet command or Card Reset SYSTem CPON command does not change the resolution setting F...

Страница 119: ...arameters in the MEASure and CONFigure commands For example the following statement selects the 10 VDC range with 4 digits of resolution on channel 301 CONF VOLT DC 10 0 001 301 The following statement selects the 1 A range with 6 digits of resolution on channel 221 MEAS CURR AC 1 1E 6 221 You can also select the resolution using the SENSe commands For example the following statement specifies a 4...

Страница 120: ...ution The only way to control the reading rate for AC measurements is by changing the channel delay see page 105 or by setting the AC filter to the highest frequency limit see page 131 The specified integration time is used for all measurements on the selected channel If you have applied Mx B scaling or have assigned alarms to the selected channel those measurements are also made using the specifi...

Страница 121: ...ctive channel INTEG 2 PLC To select the aperture time select INTEGRATE T from the Advanced menu and then specify a value in seconds for the active channel INTEGRATE T Remote Interface Operation You can set the integration time using the SENSe commands For example the following statement specifies an integration time of 10 PLC for DC voltage measurements on channel 301 SENS VOLT DC NPLC 10 301 You ...

Страница 122: ...hms and DC current measurements only Autozero is enabled when you select 4 wire ohms measurements The autozero mode is set indirectly when you set the resolution and integration time Autozero is automatically turned off when you select an integration time less than 1 PLC You can set autozero from the remote interface only you cannot directly set autozero from the front panel The autozero setting i...

Страница 123: ...You can mix temperature units on different channels within the instrument and on the same module The instrument selects Celsius when the probe type is changed and after a Factory Reset RST command An Instrument Preset SYSTem PRESet command or Card Reset SYSTem CPON command does not change the units setting Setting the Mx B measurement label to C F or K has no effect on the temperature measurement ...

Страница 124: ...ment Before configuring a thermocouple channel with an external reference you must configure the reference channel channel 01 for a thermistor or RTD measurement An error is generated if you attempt to select the external reference source before configuring the reference channel An error is also generated if you change the function on the reference channel after selecting the external reference fo...

Страница 125: ... C on the front panel Front Panel Operation To select the thermocouple function on the active channel choose the following items TEMPERATURE THERMOCOUPLE To select the thermocouple type for the active channel choose the following item J TYPE T C To enable the thermocouple check feature on the active channel opens are reported as OPEN T C choose the following item T C CHECK ON To select the referen...

Страница 126: ... thermocouple type For example the following statement configures channel 203 for a J type thermocouple measurement SENS TEMP TRAN TC TYPE J 203 The following statements use the SENSe command to set a fixed reference junction temperature of 40 degrees always in C on channel 203 SENS TEMP TRAN TC RJUN TYPE FIXED 203 SENS TEMP TRAN TC RJUN 40 203 The following statement enables the thermocouple chec...

Страница 127: ...des the most accurate way to measure small resistances Connection lead resistance is automatically removed using the 4 wire method For 4 wire RTD measurements the instrument automatically pairs channel n with channel n 10 34901A or n 8 34902A to provide the source and sense connections For example make the source connections to the HI and LO terminals on channel 2 and the sense connections to the ...

Страница 128: ... specify 0 00391 CONF TEMP RTD 85 301 You can also use the SENSe command to select the probe type RTD type and nominal resistance For example the following statement configures channel 103 for 4 wire measurements of an RTD with 0 00391 channel 103 is automatically paired with channel 113 for the 4 wire measurement SENS TEMP TRAN FRTD TYPE 91 103 The following statement sets the nominal resistance ...

Страница 129: ...the active channel choose from the following items TYPE 2 2 KOHM TYPE 5 KOHM TYPE 10 KOHM Remote Interface Operation You can use the MEASure or CONFigure command to select the probe type and thermistor type For example the following statement configures channel 301 for measurements of a 5 k thermistor CONF TEMP THER 5000 301 You can also use the SENSe command to select the probe type and thermisto...

Страница 130: ...or the 100 mVDC 1 VDC and 10 VDC ranges Applies to DC voltage measurements only The instrument selects 10 M fixed input resistance on all DC voltage ranges when the measurement function is changed or after a Factory Reset RST command An Instrument Preset SYSTem PRESet command or Card Reset SYSTem CPON command does not change the input resistance setting Front Panel Operation First select the DC vo...

Страница 131: ...ion is changed or after a Factory Reset RST command An Instrument Preset SYSTem PRESet command or Card Reset SYSTem CPON command does not change the setting Front Panel Operation First select the AC voltage or AC current function on the active channel Then go to the Advanced menu and select the slow filter 3 Hz medium filter 20 Hz or fast filter 200 Hz for the active channel The default is the med...

Страница 132: ...urrent source turned off Applies only to 2 wire and 4 wire ohms measurements on the 100 1 k and 10 k ranges For detailed information about offset compensation see page 293 The instrument disables offset compensation when the measurement function is changed or after a Factory Reset RST command An Instrument Preset SYSTem PRESet command or Card Reset SYSTem CPON command does not change the setting F...

Страница 133: ...e you to either optimize low frequency accuracy or achieve faster AC settling times The instrument selects the slow medium or fast filter based on the input frequency that you specify for the selected channels Applies to AC current and AC voltage measurements only The instrument selects the medium filter 20 Hz when the function is changed or after a Factory Reset RST command An Instrument Preset S...

Страница 134: ...active channel The default is the medium filter LF 3 HZ SLOW Remote Interface Operation Specify the lowest frequency expected in the input signal on the specified channels The instrument selects the appropriate filter based on the frequency you specify see table on previous page The MEASure and CONFigure commands automatically select the 20 Hz medium filter SENS VOLT AC BAND 3 203 Select the slow ...

Страница 135: ...e the setting Front Panel Operation First select the frequency function on the active channel Then go to the Advanced menu and select the slow timeout 3 Hz medium timeout 20 Hz or fast timeout 200 Hz for the active channel The default is the medium timeout value LF 3 HZ SLOW Remote Interface Operation Specify the lowest frequency expected in the input signal on the specified channels The instrumen...

Страница 136: ... you change the temperature probe type temperature units or disable the internal DMM If you plan to use scaling on a channel which will also use alarms be sure to configure the scaling values first If you attempt to assign the alarm limits first the instrument will turn off alarms and clear the limit values when you enable scaling on that channel If you specify a custom measurement label with scal...

Страница 137: ...racter in the label The remaining two characters can be letters numbers or an underscore Note If you set the measurement label to C F or K note that this has no effect on the temperature units set in the Measure menu Although the instrument does not directly support strain gage measurements you can measure a strain gage using a 4 wire resistance measurement with scaling For more information refer ...

Страница 138: ...faults go to the corresponding level in the menu and turn the knob To turn scaling off without clearing the gain and offset values go to the first level in the menu and select SCALING OFF SET GAIN TO 1 SET OFST TO 0 DEFAULT LABEL To make a null measurement and store it as the offset go to SET OFFSET in the menu and turn the knob SET OFFSET Remote Interface Operation Use the following commands to s...

Страница 139: ... stored in one of two locations depending on whether a scan is running when the alarm occurs 1 If an alarm event occurs on a channel as it is being scanned that channel s alarm status is stored in reading memory as the readings are taken Each reading outside the specified alarm limits is logged in memory You can store up to 50 000 readings in memory during a scan You can read the contents of readi...

Страница 140: ...arms on a channel which will also use scaling be sure to configure the scaling values first If you attempt to assign the alarm limits first the instrument will turn off alarms and clear the limit values when you enable scaling on that channel If you specify a custom measurement label with scaling it is automatically used when alarms are logged on that channel If you remove a channel from the scan ...

Страница 141: ...t is logged on a channel For complete details refer to Using the Alarm Output Lines on page 145 The following table shows the different combinations of front panel annunciators that may appear while using alarms An alarm is enabled on the displayed channel The indicated HI or LO limit is being configured on the indicated alarm shown while in the Alarm menu An alarm has occurred on one or more chan...

Страница 142: ...lears all alarm limits and turns off all alarms An Instrument Preset SYSTem PRESet command or Card Reset SYSTem CPON command does not clear the alarm limits and does not turn off alarms Front Panel Operation To select the alarm for use on the active channel choose from the following items NO ALARM USE ALARM 1 USE ALARM 4 Then choose from the following alarm conditions HI LO ALARMS HI ALARM ONLY LO...

Страница 143: ...s of reading memory at any time even during a scan Reading memory is not cleared when you read it Each time you start a new scan the instrument clears all readings including alarm data stored in reading memory from the previous scan Therefore the contents of memory are always from the most recent scan Up to 20 alarms can be logged in the alarm queue If more than 20 alarms are generated they will b...

Страница 144: ...rm stored in the alarm queue if no alarm data is in the queue the command returns 0 for each field The following command retrieves scanned readings and alarm data from reading memory the readings are not erased FETCH 1 Reading with Units 31 009 C 2 Date May 1 1997 3 Time 2 39 40 058 PM 4 Channel Number 5 Limit Threshold Crossed 0 No Alarm 1 LO 2 HI 6 Alarm Number Reported 1 2 3 or 4 34970A Refresh...

Страница 145: ...scribed below The behavior of the alarm annunciators on the front panel also tracks the alarm output configuration The configuration that you select is used for all four alarm output lines A Factory Reset RST command clears all four alarm outputs but does not clear the alarm queue in either configuration Latch Mode In this mode the corresponding output line is latched true when the first alarm occ...

Страница 146: ...selected configuration is used for all four outputs In the falling edge mode 0V TTL low indicates an alarm In the rising edge mode 5V TTL high indicates an alarm A Factory Reset RST command will reset the slope to falling edge Note Changing the slope of the output lines may cause the lines to change state Front Panel Operation To specify if you want to manually clear all four alarm outputs choose ...

Страница 147: ...LARM2 CLEAR Clear alarm output line 2 OUTPUT ALARM CLEAR ALL Clear all four alarm outputs To select the output configuration for all four output lines use the following command OUTPut ALARm MODE LATCh TRACk To configure the slope of all four output lines use the following command OUTPut ALARm SLOPe NEGative POSitive 34970A Refresh UG book Page 147 Wednesday February 17 2010 12 34 PM ...

Страница 148: ... instrument clears all readings including alarm data stored in reading memory from the previous scan However alarm data stored in the alarm queue from the multifunction module is not cleared Therefore although the contents of reading memory are always from the most recent scan the alarm queue may contain data that occurred during previous scans or while the instrument was not scanning Front Panel ...

Страница 149: ... EQUal NEQual ch_list COMPare DATA data ch_list COMPare MASK mask ch_list Select EQUal to generate an alarm when the data read from the port is equal to CALC COMP DATA after being masked by CALC COMP MASK Select NEQual not equal to generate an alarm when the data read from the port is not equal to CALC COMP DATA after being masked by CALC COMP MASK Use CALC COMP MASK to designate the don t care bi...

Страница 150: ...n Totalizer Channel To assign the alarm number to report any alarm conditions on the specified totalizer channels use the following command OUTPut ALARm 1 2 3 4 SOURce ch_list To configure an alarm on a totalizer channel specify the desired count as the upper limit using the following command CALCulate LIMit UPPer count ch_list To enable the upper limit on the specified totalizer channel use the f...

Страница 151: ...ncluded in the scan list you can still perform low level read operations on the port but you cannot perform write operations on the port From the front panel you can read data from only one 8 bit input port at a time From the remote interface you can read both ports simultaneously as a 16 bit word only if neither port is in the scan list If one or both ports are included in the scan list you can r...

Страница 152: ...t To add a digital read to a scan list choose the following item DIO READ From the front panel only you can specify whether you want to use binary or decimal format USE DECIMAL USE BINARY Remote Interface Operation From the remote interface you can read an 8 bit byte from one port or a 16 bit word from both ports using the following commands If you are going to read both ports simultaneously you m...

Страница 153: ...talizer actually records counts by providing a gate signal G and terminals on the module A TTL high signal applied to the G terminal enables counting and a low signal disables counting A TTL low signal applied to the terminal enables counting and a high signal disables counting The totalizer only counts when both terminals are enabled You can use either the G terminal the terminal or both When a g...

Страница 154: ...ver it is read directly by pressing from the front panel or when sending the SENSe TOTalize DATA command You can configure the instrument to generate an alarm when a specific count is reached on a totalizer channel These channels do not have to be part of the scan list to generate an alarm Alarms are evaluated continuously as soon as you enable them For more information see Using Alarms With the M...

Страница 155: ...l you press another key turn the knob or until the display times out To configure the totalizer reset mode choose from the following items READ READ RESET To configure the totalizer to count on the falling edge or rising edge of the input signal choose from the following items COUNT FALLING COUNT RISING To add a totalizer read to a scan list choose the following item TOT READ 34970A Refresh UG boo...

Страница 156: ...onfigure the totalizer reset mode send either of the following commands RRESet means read and reset SENSe TOTalize TYPE READ RRESet ch_list CONFigure TOTalize READ RRESet scan_list To configure the totalizer to count on the falling edge negative or rising edge positive of the input signal send the following command SENSe TOTalize SLOPe NEG POS ch_list To immediately clear the count on the specifie...

Страница 157: ... you want to use binary or decimal format Once you have selected the number base it is used for all input or output operations on the same port A Factory Reset RST command Instrument Preset SYSTem PRESet command and Card Reset SYSTem CPON command from the remote interface will reconfigure both ports as input ports Note A from the front panel resets only the port currently selected both ports are n...

Страница 158: ...word to both ports simultaneously using the following commands You must specify a decimal value binary data is not accepted If you are going to read both ports simultaneously you must send the command to port 01 SOUR DIG DATA BYTE 10 302 Write to port 02 SOUR DIG DATA WORD 10327 301 Write to both ports 34970A Refresh UG book Page 158 Wednesday February 17 2010 12 34 PM ...

Страница 159: ...earth referenced it cannot float Each DAC channel is capable of 10 mA maximum output current Note You must limit the output current to 40 mA total for all three slots six DAC channels A Factory Reset RST command Instrument Preset SYSTem PRESet command and Card Reset SYSTem CPON command from the remote interface will reset both DACs to 0 VDC Note A from the front panel resets only the DAC currently...

Страница 160: ...tate from a location that contains a previously stored state You can use location 0 to store a sixth instrument state However keep in mind that location 0 is automatically overwritten when power is cycled The instrument stores the state of all modules including all channel configurations scanning setups alarm values and scaling values When shipped from the factory storage locations 1 through 5 are...

Страница 161: ...does not affect the configurations stored in memory Once a state is stored it remains until it is overwritten or specifically deleted Front Panel Operation NAME STATE STORE STATE RECALL STATE After recalling a stored state you will notice that a new choice UNDO RECALL is added under RECALL STATE This allows you to cancel the last recall operation and revert to the previous state You can also selec...

Страница 162: ...g command From the remote interface you can only recall a stored state using a number 0 through 5 MEM STATE NAME 1 TEST_RACK_1 To configure the instrument to automatically issue a Factory Reset RST command when power is restored send the following command MEMory STATe RECall AUTO OFF 34970A Refresh UG book Page 162 Wednesday February 17 2010 12 34 PM ...

Страница 163: ...ith Error queue overflow No additional errors are stored until you remove errors from the queue If no errors have occurred when you read the error queue the instrument responds with No error The error queue is cleared by the CLS clear status command or when power is cycled The errors are also cleared when you read the queue The error queue is not cleared by a Factory Reset RST command or an Instru...

Страница 164: ...ce that the instrument and all installed plug in modules are operational If the complete self test is successful PASS is displayed on the front panel If the self test fails FAIL is displayed and the ERROR annunciator turns on See the 34970A 34972A Service Guide for instructions on returning the instrument to Agilent for service Front Panel Operation To perform the complete front panel self test ho...

Страница 165: ... a Factory Reset RST command or when you return to local by pressing You can display a message on the front panel by sending a command from the remote interface The instrument can display up to 13 characters on the front panel if you attempt to send more than 13 characters an error is generated You can use letters A Z numbers 0 9 and special characters like etc Use the character to display a degre...

Страница 166: ... DISPLAY TEXT CLEAR Real Time System Clock During a scan the instrument stores all readings and alarms with the current time and date The instrument stores the time and date information in non volatile memory When shipped from the factory the instrument is set to the current time and date U S Mountain Time Front Panel Operation TIME 03 45 PM JUN 01 1997 Remote Interface Operation Use the following...

Страница 167: ...et command does not affect the internal DMM configuration Front Panel Operation DMM ENABLED DMM DISABLED Remote Interface Operation INSTrument DMM OFF ON Firmware Revision Query The instrument has three microprocessors for control of various internal systems Each plug in module also has its own on board microprocessor You can query the instrument and each module to determine which revision of firm...

Страница 168: ...acters IDN The above command returns a string in the form HEWLETT PACKARD 34970A 0 X X Y Y Z Z Agilent Technologies 34972A 0 I II O OO FP FPGA See the Agilent 34970A 34972A Programmer s Reference Help for details Use the following command to read the firmware revision number of the module in the specified slot be sure to dimension a string variable with at least 30 characters SYSTem CTYPe 100 200 ...

Страница 169: ...nd K104 respectively These relays open or close when a function or range is changed on a module The 34908A multiplexer contains 40 channels which are switched HI only using only 20 relays Each relay is used to switch HI on two different channels and only one channel can be closed at a time The channels are arranged such that channels 01 and 21 use different contacts on the same relay The remaining...

Страница 170: ...nob clockwise beyond the highest numbered channel in the current slot RELAY CYCLES Remote Interface Operation To read the relay count on either the internal DMM all three relays or the specified module channels send the following commands DIAG DMM CYCLES DIAG RELAY CYCLES 305 399 To clear the count on either the specified internal DMM relay or the specified module channels the instrument must be u...

Страница 171: ...annel being monitored at any time Readings acquired during a Monitor are not stored in memory but they are displayed on the front panel however all readings from a scan in progress at the same time are stored in memory Mx B scaling and alarm limits are applied to the selected channel during a Monitor and all alarm data is stored in the alarm queue which will be cleared if power fails A scan in pro...

Страница 172: ...Monitor press Turn the knob to advance to the desired channel The instrument begins monitoring after you pause for a few seconds on a configured channel To stop a Monitor press again Note that while the instrument is in the remote mode you can still turn on the Monitor function and select the desired channel Remote Interface Operation The following program segment selects the channel to be monitor...

Страница 173: ...ne the SCPI version with which the instrument is in compliance by sending a command from the remote interface You cannot query the SCPI version from the front panel The following command returns the SCPI version SYSTem VERSion Returns a string in the form YYYY V where YYYY represents the year of the version and V represents a version number for that year for example 1994 0 34970A Refresh UG book P...

Страница 174: ...n reading memory If you are using TRIGger COUNt INFinity and capturing more than 50 000 readings reading memory will fill and then overflow discarding the oldest data The USB streaming will continue after reading memory overflows allowing you to capture all of the data up to 232 sweeps or up to the limits imposed by the USB drive 2 Copying of data from reading memory to USB drive Files are automat...

Страница 175: ...ent s IP address in place of AAA BBB CCC DDD The software will ask for a user name and password The user name is Anonymous and the password is any string such as xyz Enter the command CD DATA to log onto the USB drive Enter the command DIR to obtain a directory of the USB drive Enter the command CD MY00012345 20091210_134523123 to change to the directory containing the data you wish to download fr...

Страница 176: ...176 Chapter 4 Features and Functions Mass Memory USB Subsystem 34972A 34970A Refresh UG book Page 176 Wednesday February 17 2010 12 34 PM ...

Страница 177: ...ation_file MMEMory IMPort CATalog For more information on the SCPI commands available to program the instrument over the remote interface see the MMEMory commands in the Agilent 34970A 34972A Programmer s Reference Help Folder and File Structure Folder Description Each saved scan will be stored in a top level folder named 34972A data instrument_SN yyyymmdd_hhmmssmmm The square brackets are not act...

Страница 178: ...addition to the config csv file you will have one or more data files named as follows dat csv If you use the command MMEMory FORMat READing RLIMit OFF all of the data will be stored in one file named dat00001 csv You can issue the command MMEMory FORMat READing RLIMit ON to limit the data to 64K 1 65 535 sweeps per file in which case the sweeps are stored in multiple files named dat00001 csv dat00...

Страница 179: ...mat for all USB data files is similar to what Agilent BenchLink Data Logger produces by default The default field separator is a comma but you can use the following command to specify a different separator MMEMory FORMat READing CSEParator TAB COMMa SEMicolon Module Description Channels 34901A 20 channel 2 wire armature multiplexer s01 s20 34902A 16 channel 2 wire reed multiplexer s01 s16 34907A 2...

Страница 180: ... previous file Thus the first scan in the second data file would be number 65 536 the first scan in the third data file would be number 131 071 and so on Sweep Time Chan 201 VDC Chan 202 VDC 1 01 26 2009 08 07 12 237 0 36823663 1 23895216 2 01 26 2009 08 07 13 237 0 62819233 0 98372939 3 01 26 2009 08 07 14 237 0 38238212 0 39382906 4 01 26 2009 08 07 15 237 0 46773299 0 55543345 5 01 26 2009 08 0...

Страница 181: ... on the SCPI commands available to configure the USB drive over the remote interface see the MMEMory Subsystem in hte Agilent 34970A 34972A Programmer s Reference Help Setting up Automatic Logging You can set up the USB drive for automatic logging of readings Front Panel Operation LOG READINGS AUTO OFF Exporting Readings You can export readings from reading memory onto the USB drive Front Panel Op...

Страница 182: ... whether the files are formatted with a tab comma or semicolon between columns Front Panel Operation FORMAT READNG ROWS FILE AUTO FORMAT READNG ROWS FILE 64K FORMAT READNG SEP TAB FORMAT READNG SEP COMMA FORMAT READNG SEP SEMICOLON Importing an Instrument Configuration You can import an instrument configuration stored in an Agilent BenchLink Data Logger configuration BLCFG file in the root directo...

Страница 183: ...interface must have a unique address You can set the instrument s address to any value between 0 and 30 The address is set to 9 when the instrument is shipped from the factory The GPIB address is displayed at power on You can set the GPIB address from the front panel only The address is stored in non volatile memory and does not change when power has been off after a Factory Reset RST command or a...

Страница 184: ...n off after a Factory Reset RST command or after an Instrument Preset SYSTem PRESet command If you select the GPIB interface you must select a unique address for the instrument The GPIB address is displayed on the front panel when you turn on the instrument If you select the RS 232 interface you must also set the baud rate parity and flow control mode for the instrument RS 232 is displayed on the ...

Страница 185: ...er an Instrument Preset SYSTem PRESet command Front Panel Operation 19200 BAUD Parity Selection RS 232 You can select the parity for RS 232 operation The instrument is configured for no parity with 8 data bits when shipped from the factory You can set the parity from the front panel only Select one of the following None 8 data bits Even 7 data bits or Odd 7 data bits When you set the parity you ar...

Страница 186: ...until the XOFF character 13H is received When the XON character 11H is received the instrument resumes sending data DTR DSR In this mode the instrument monitors the state of the DSR data set ready line on the RS 232 connector When the line goes true the instrument sends data over the interface When the line goes false the instrument stops sending information typically within six characters The ins...

Страница 187: ...true when it is ready to receive data The modem sets the CTS line true when it is ready to accept data The instrument sets the RTS line false when the input buffer is almost full approximately 100 characters and releases the line when space is available again The flow control selection is stored in non volatile memory and does not change when power has been off after a Factory Reset RST command or...

Страница 188: ...d under the top level menu LAN INTERFACE Enabling and Disabling LAN Connectivity You can enable or disable the LAN connectivity If you are not controlling the instrument via LAN it is a good idea to disable LAN connectivity in order to prevent others from connecting to your instrument over the LAN Front Panel Operation LAN ENABLED DISABLED Determining the Status of LAN Connectivity You can determi...

Страница 189: ...ry to obtain an IP address from a DHCP server If a DHCP server is found it will assign a dynamic IP address Subnet Mask and Default Gateway to the instrument If a DHCP server is not found the instrument uses AutoIP to automatically configure its IP setting in the Automatic Private IP Addressing range 169 254 xxx xxx When DHCP is disabled the instrument will use the static IP address Subnet Mask De...

Страница 190: ...with this feature Front Panel Operation IP ADDRESS Setting the Subnet Mask You can set the subnet mask for your LAN connection This menu option assigns a Subnet Mask for the instrument The instrument uses the Subnet Mask to determine whether a client IP address is on the same local subnet You must disable DHCP in order to set this on the front panel When a client IP address is on a different subne...

Страница 191: ...AN connection Contact your network administrator to determine whether DNS is being used and for the correct address If DHCP is available and enabled DHCP will auto assign the DNS address This auto assigned DNS address takes precedence over the static DNS address assigned with this menu option You must disable DHCP in order to set this on the front panel Front Panel Operation DNS SERVER Viewing the...

Страница 192: ...set to either HP034970 or AT034972 depending on the product number when the instrument is shipped from the factory The security code is stored in non volatile memory on the mainframe and does not change when power has been off after a Factory Reset RST command or after an Instrument Preset SYSTem PRESet command The security code may contain up to 12 alphanumeric characters The first character must...

Страница 193: ...that same code to unsecure it from the remote interface Front Panel Operation UNSECURE CAL When you first enter the Utility menu the calibration entries toggle between CAL SECURED and UNSECURE CAL To unsecure the instrument select UNSECURE CAL and press After entering the correct security code press again When you return to the menu you will see new choices CAL UNSECURED and SECURE CAL Note If you...

Страница 194: ...oices CAL SECURED and UNSECURE CAL Remote Interface Operation To secure the instrument send the following command with the desired security code CAL SECURE STATE ON HP034970 To Change the Security Code To change the security code you must first unsecure the instrument and then enter a new code Make sure you have read the security code rules described on page 155 before attempting to change the sec...

Страница 195: ... You can read the calibration message whether the instrument is secured or unsecured The calibration message may contain up to 40 characters From the front panel you can view 13 characters of the message at a time Press to scroll through the text of the message Press again to increase the scrolling speed Storing a calibration message will overwrite any message previously stored in memory The calib...

Страница 196: ...nd does not change when power has been off after a Factory Reset RST command or after an Instrument Preset SYSTem PRESet command The calibration count increments up to a maximum of 65 535 after which it rolls over to 0 Since the value increments by one for each calibration point a complete calibration may increase the value by many counts The calibration count is also incremented with calibrations...

Страница 197: ...nitor in Progress Factory Reset State Empty All Readings are Cleared Not Changed Immediate 10 Seconds 1 Reading Only No Units Channel Time Stopped Mx B Scaling Gain Factor M Scale Factor B Scale Label Factory Reset State 1 0 VDC Alarm Limits Alarm Queue Alarm State HI and LO Alarm Limits Alarm Output Alarm Output Configuration Alarm Output State Alarm Output Slope Factory Reset State Not Cleared O...

Страница 198: ...l Readings are Cleared No Change No Change No Change No Change No Change Stopped Mx B Scaling Gain Factor M Scale Factor B Scale Label Instrument Preset State No Change No Change No Change Alarm Limits Alarm Queue Alarm State HI and LO Alarm Limits Alarm Output Configuration Alarm Output State Alarm Output Slope Instrument Preset State No Change No Change No Change No Change Output Lines are Clear...

Страница 199: ...atic Delay Voltage Measurements Range Resolution Integration Time Input Resistance AC Low Frequency Filter Channel Delay Default Setting Autorange 5 digits 1 PLC 10 M fixed for all DCV ranges 20 Hz medium Automatic Delay Resistance Measurements Range Resolution Integration Time Offset Compensation Channel Delay Default Setting Autorange 5 digits 1 PLC Off Automatic Delay Frequency Period Measureme...

Страница 200: ...cations on each plug in module refer to the module sections in chapter 8 34901A 20 Channel Multiplexer on page 201 34902A 16 Channel Multiplexer on page 203 34903A 20 Channel Actuator on page 205 34904A 4x8 Matrix Switch on page 207 34905A 6A Dual 4 Channel RF Multiplexers on page 209 34907A Multifunction Module on page 211 34908A 40 Channel Single Ended Multiplexer on page 213 34970A Refresh UG b...

Страница 201: ...reference junction to minimize errors due to thermal gradients when measuring thermocouples NOTES Only one of channels 21 and 22 can be connected to the internal DMM and or Com at a time connecting one channel will close the other thus shorting the input I to LO If any channels are configured to be part of the scan list you cannot close multiple channels closing one channel will open the previousl...

Страница 202: ...50 W WARNING To prevent electrical shock use only wire that is rated for the highest voltage applied to any channel Before removing a module cover turn off all power to external devices connected to the module WIRING LOG Slot Number 100 200 300 Ch Name Function Comments 01 02 03 04 05 06 07 08 09 10 H COM L COM 11 12 13 14 15 16 17 18 19 20 H COM L COM Current Channels Only 21 22 I COM L COM 6mm 2...

Страница 203: ...couple reference junction to minimize errors due to thermal gradients when measuring thermocouples NOTES If any channels are configured to be part of the scan list you cannot close multiple channels closing one channel will open the previously closed channel Current measurements on this module will require external shunt resistors Connections to AC line are not recommended unless you provide exter...

Страница 204: ...m Switching Power 2 W WARNING To prevent electrical shock use only wire that is rated for the highest voltage applied to any channel Before removing a module cover turn off all power to external devices connected to the module WIRING LOG Slot Number 100 200 300 Ch Name Function Comments 01 02 03 04 05 06 07 08 H COM L COM 09 10 11 12 13 14 15 16 H COM L COM 6mm 20 AWG Typical 34970A Refresh UG boo...

Страница 205: ...mplement custom circuitry such as simple filters snubbers and voltage dividers The breadboard area provides the space necessary to insert your own components but there are no circuit board traces here You must add your own circuitry and signal routing NOTES You can close multiple channels at the same time on this module The channel CLOSE and OPEN commands control the state of the Normally Open NO ...

Страница 206: ...um Switching Power 50 W WARNING To prevent electrical shock use only wire that is rated for the highest voltage applied to any channel Before removing a module cover turn off all power to external devices connected to the module WIRING LOG Slot Number 100 200 300 Ch NO NC COM Comments 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 6mm 20 AWG Typical 34970A Refresh UG book Page 206 Wed...

Страница 207: ...e This module does not connect to the internal DMM Each crosspoint relay has its own unique channel label representing the row and column For example channel 32 represents the crosspoint connection between row 3 and column 2 as shown below NOTES You can close multiple channels at the same time on this module Row 1 Row 2 Row 3 Row 4 Col 1 Col 2 Col 8 Channel 32 Row 3 Column 2 Row 2 34970A Refresh U...

Страница 208: ...rrent 1 A Maximum Switching Power 50 W WARNING To prevent electrical shock use only wire that is rated for the highest voltage applied to any channel Before removing a module cover turn off all power to external devices connected to the module WIRING LOG Slot Number 100 200 300 Row Name Comments 1 2 3 4 Column Name Comments 1 2 3 4 5 6 7 8 6mm 20 AWG Typical 34970A Refresh UG book Page 208 Wednesd...

Страница 209: ...MB connectors or to the SMB to BNC cables provided with the module NOTES The 34905A is used for 50 applications The 34906A is used for 75 applications mini SMBs You can close only one channel per bank at a time on these modules closing one channel in a bank will open the previously closed channel One channel in each bank is always connected to COM This module responds only to the CLOSE command OPE...

Страница 210: ...700 mA Maximum Switching Power 20 W Ten color coded cables are included with the module To order additional cables use the following cable kit part numbers 10 cables are included 34905 60001 50 cables 34906 60001 75 cables WIRING LOG Slot Number 100 200 300 Ch Name Comments 11 12 13 14 COM1 21 22 23 24 COM2 SMB to BNC Cable 34970A Refresh UG book Page 210 Wednesday February 17 2010 12 34 PM ...

Страница 211: ...or falling edge of the input signal A TTL high signal applied to the G terminal enables counting and a low signal disables counting A TTL low signal applied to the terminal enables counting and a high signal disables counting The totalizer only counts when both terminals are enabled Move the Totalize Threshold jumper to the AC position to detect changes through 0 volts Move the jumper to the TTL p...

Страница 212: ...ll up Totalizer Maximum Count 67 108 863 226 1 Totalize Input 100 kHz max Signal Level 1 Vp p min 42 Vpk max DAC Output 12V non isolated lout 10 mA max per DAC 40 mA max per mainframe WIRING LOG Slot Number 100 200 300 Ch Name Comments 01 DIO 1 Bit 0 Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 7 GND 02 DIO 2 Bit 0 Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 7 GND 03 Totalizer Input Input Gate 04 DAC 1 Out...

Страница 213: ...asurements When connecting thermocouples to the screw terminals on this module not recommended due to the common LO configuration be sure to provide electrical isolation between thermocouples to avoid current loops and subsequent measurement errors Connections to AC line are not recommended unless you provide external transient Maximum Input Voltage 300 V CAT I Maximum Input Current 1 A Maximum Sw...

Страница 214: ...tiplexer WIRING LOG Slot Number 100 200 300 Ch Name Function Comments 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 LO H COM L COM 34970A Refresh UG book Page 214 Wednesday February 17 2010 12 34 PM ...

Страница 215: ...215 Chapter 4 Features and Functions 34908A 40 Channel Single Ended Multiplexer 4 34970A Refresh UG book Page 215 Wednesday February 17 2010 12 34 PM ...

Страница 216: ...216 Chapter 4 Features and Functions 34908A 40 Channel Single Ended Multiplexer 34970A Refresh UG book Page 216 Wednesday February 17 2010 12 34 PM ...

Страница 217: ...5 5 Error Messages 34970A Refresh UG book Page 217 Wednesday February 17 2010 12 34 PM ...

Страница 218: ...ument responds with No error The error queue is cleared by the CLS clear status command or when power is cycled The errors are also cleared when you read the queue The error queue is not cleared by a Factory Reset RST command or an Instrument Preset SYSTem PRESet command Front Panel Operation ERRORS If the ERROR annunciator is on press to view the errors Use the knob to scroll through the error nu...

Страница 219: ...igger GET is not allowed within a command string 108 Parameter not allowed More parameters were received than expected for this command You may have entered an extra parameter or added a parameter to a command that does not require a parameter Example READ 10 109 Missing parameter Fewer parameters were received than expected for this command You have omitted one or more parameters that are require...

Страница 220: ...was found whose mantissa contained more than 255 digits excluding leading zeros 128 Numeric data not allowed The wrong parameter type was found in the command string You may have specified a number where a string or expression was expected or vice versa Examples DISP TEXT 5 0 or ROUT CLOSE 101 131 Invalid suffix A suffix was incorrectly specified for a numeric parameter You may have misspelled the...

Страница 221: ... command Check the list of parameters to verify that you have used a valid parameter type Example CALC SCALE STATE ON 168 Block data not allowed Data was sent to the instrument in SCPI definite length block format but this command does not accept this format Example SOUR DIG DATA 128 178 Expression data not allowed A channel list was received but is not allowed for this command Example SYST CTYPE ...

Страница 222: ...his command Example TRIG COUNT 3 223 Too much data A character string was received but could not be executed because the string length was more than 12 characters This error can be generated by the CAL STRing and DISPlay TEXT commands 224 Illegal parameter value A discrete parameter was received which was not a valid choice for this command You may have used an invalid parameter choice Example TRI...

Страница 223: ... bus Device Clear 420 Query UNTERMINATED The instrument was addressed to talk i e send data over the interface but a command has not been received which sends data to the output buffer For example you may have executed a CONFigure command which does not generate data and then attempted to read data from the remote interface 430 Query DEADLOCKED A command was received which generates too much data ...

Страница 224: ... which includes all configured multiplexer or digital channels in the instrument Use the MEASure CONFigure or ROUTe SCAN commands to set up your scan list 201 Memory lost stored state This error is reported at power on to indicate that a stored state has become unusable This error is most likely caused by a dead battery memory is battery backed Refer to the 34970A 34972A Service Guide to replace t...

Страница 225: ...pt to assign the alarm limits first and the instrument will turn off alarms and clear the limit values 222 Settings conflict module type does not match stored state Before recalling a stored state the instrument verifies that the same module types are installed in each slot The instrument has detected a different module type in one or more slots 223 Settings conflict trig source changed to IMM Thi...

Страница 226: ...5000 and 10 k 10000 Example CONF TEMP RTD 1 101 261 Not able to execute while scan initiated While a scan is running you cannot change any parameters that affect the scan channel configuration scan interval scaling values alarm limits issue a Card Reset or recall a stored state To stop a scan in progress send the ABORt command or a bus Device Clear 271 Not able to accept unit names longer than 3 c...

Страница 227: ...Internal DMM Disable on page 167 301 Module currently committed to scan When you add a multiplexer channel to a scan list that entire module is dedicated to the scan You cannot perform low level close or open operations on any channels on that module even those channels that are not configured To stop a scan in progress send the ABORt command or a bus Device Clear 303 Module not able to perform re...

Страница 228: ...ouple channel with an external reference you must configure the reference channel channel 01 for a thermistor or RTD measurement This error is also generated if you change the function on the reference channel channel 01 after selecting the external reference source on a thermocouple channel 308 Channel not able to perform requested operation The channel is unable to perform the requested operatio...

Страница 229: ...Mass storage error failed to remove file The instrument was unable unable to delete the file on the USB drive 408 Mass storage error failed to create directory The instrument was unable to create the directory on the USB drive 409 Mass storage error failed to remove directory The instrument was unable to remove the directory on the USB drive 410 Not enough disk space The external USB drive is full...

Страница 230: ...415 File not found The file does not exist on the USB drive 416 Path not found The directory does not exist on the USB drive 417 File not opened for writing The instrument failed to open the file for writing on the USB drive 418 File not opened for reading The instrument failed to open the file for reading from the USB drive 34970A Refresh UG book Page 230 Wednesday February 17 2010 12 34 PM ...

Страница 231: ...ly logged to USB 454 Not able to execute while copying data to USB Operation can not be completed while data is being exported to USB 455 Not able to execute while importing a configuration from USB Operation can not be completed while a measurement configuration is being imported from USB 457 Logging request ignored USB device is busy Logging was not started because USB is busy but the scan will ...

Страница 232: ...uring configuration import 464 Invalid import file The instrument did not recognize the USB configuration import file 465 Import file cardset does not match instrument The current instrument configuration does not match the cardset expected by the USB import file 466 Operation not allowed in a configuration import file An illegal command was used inside the USB import file 467 No readings to expor...

Страница 233: ...guration data will not be saved to the USB drive 472 One or more blcfg file names invalid files inaccessible Agilent BenchLink Data Logger BLCFG configuration files on the USB drive are limited to 40 character filenames including the blcfg extension and all characters must be ANSI Only legal filenames will be selectable for import 473 Disk contains too many blcfg files oldest files inaccessible In...

Страница 234: ...d operation is not allowed because another I O session has locked the instrument 521 Communications input buffer overflow 522 Communications output buffer overflow 532 Not able to achieve requested resolution The instrument cannot achieve the requested measurement resolution You may have specified an invalid resolution in the CONFigure or MEASure command 540 Not able to null channel in overload Th...

Страница 235: ...onfiguration readback 609 Self test DC gain x1 610 Self test DC gain x10 611 Self test DC gain x100 612 Self test Ohms 500 nA source 613 Self test Ohms 5 uA source 614 Self test DC 300V zero 615 Self test Ohms 10 uA source 616 Self test DC current sense 617 Self test Ohms 100 uA source 618 Self test DC high voltage attenuator 619 Self test Ohms 1 mA source 620 Self test AC rms zero 621 Self test A...

Страница 236: ... 12 characters but the first character must always be a letter The security code is set to HP034970 or AT034972 when the instrument is shipped from the factory 704 Cal secure code too long The security code may contain up to 12 alphanumeric characters A security code was received which contained more than 12 characters 705 Cal aborted A calibration in progress is aborted when you turn off the inst...

Страница 237: ...ncy convergence failed 734 Cal AC low frequency correction out of range 735 Cal AC rms converter noise correction out of range 736 Cal AC rms 100th scale correction out of range 740 Cal data lost secure state 741 Cal data lost string data 742 Cal data lost DCV corrections 743 Cal data lost DCI corrections 744 Cal data lost RES corrections 745 Cal data lost FRES corrections 746 Cal data lost AC cor...

Страница 238: ... only Config data lost HP IB address 747 34972A only Calibration failed 748 34970A only Config data lost RS 232 748 34972A only Cal checksum failed internal data 749 DMM relay count data lost 34970A Refresh UG book Page 238 Wednesday February 17 2010 12 34 PM ...

Страница 239: ...ware not responding 910 Module reported an unknown module type 911 Module reported command buffer overflow 912 Module reported command syntax error 913 Module reported nonvolatile memory fault 914 Module reported temperature sensor fault 915 Module reported firmware defect 916 Module reported incorrect firmware installed NOTE The following error messages indicate possible hardware failures within ...

Страница 240: ...240 Chapter 5 Error Messages Plug In Module Errors 34970A Refresh UG book Page 240 Wednesday February 17 2010 12 34 PM ...

Страница 241: ...6 6 Application Programs 34970A Refresh UG book Page 241 Wednesday February 17 2010 12 34 PM ...

Страница 242: ...cture library for use with your GPIB interface card in your PC You will want to make sure that you have the visa32 dll file in your c windows system directory for the examples to work properly These programs were written for the 34970A but other than the connectivity the principles and code should generally apply to the 34972A as well For programs specific to the 34972A see the product page at www...

Страница 243: ... shown on page 244 into the Send Commands module Then type the text for configuring the interface as shown on page 245 into the Port Configuration module After entering the information for both modules go to a spreadsheet and run the example program Note that you must run the macro from a spreadsheet With the cursor in the spreadsheet select Macro from the Tools menu Then double click on the takeR...

Страница 244: ... this section to select the number of readings channel delay and channel number to be measured numberMeasurements 10 Number of readings measurementDelay 0 1 Delay in secs between relay closure and measurement Configure the function range and channel SendSCPI CONF VOLT DC 103 Configure channel 103 for DC voltage Select channel delay and number of readings SendSCPI ROUT CHAN DELAY Str measurementDel...

Страница 245: ...on your PC This routine uses the VTL Library to send commands to the instrument A description of these and additional VTL commands can be found in the Agilent VISA User s Guide Public Sub SendSCPI SCPICmd As String This routine sends a SCPI command string to the GPIB port If the command is a query command contains a question mark you must read the response with getScpi Dim commandstr As String Com...

Страница 246: ...ddr INSTR 0 2500 vi If an error occurs give a message If errorStatus VI_SUCCESS Then Range A2 Select Cells 1 1 Unable to Open Port End If End Sub Sub ClosePort errorStatus viClose vi Close the session errorStatus viClose videfaultRM End Sub This subroutine is used to create delays The input is in seconds and fractional seconds are allowed Sub delay delay_time As Single Dim Finish As Single Finish ...

Страница 247: ...GPIB SendSCPI RST Issue a Factory Reset to the instrument SET UP Modify this section to select the scan interval the scan count and channel delay These are variables that are used to set the scan parameters ScanInterval 10 Delay in secs between scans numberScans 3 Number of scan sweeps to measure channelDelay 0 1 Delay in secs between relay closure and measurement To delete channels from the scan ...

Страница 248: ...sweeps For columnIndex 1 To numberScans Start of scan data Do Wait for instrument to put a reading in memory SendSCPI DATA POINTS Get the number of readings stored points Val GetSCPI Loop Until points 1 Remove one reading at a time from memory For Channel 1 To numberChannels SendSCPI DATA REMOVE 1 Request one reading from memory Application ScreenUpdating False Get readings from buffer and store i...

Страница 249: ...ndex 2 Cells 1 1 Get the time stamp and put into the column to the right of data to convert relative time to Excel time divide by 86400 Cells Channel 4 columnIndex 2 1 Cells 1 2 86400 Cells Channel 4 columnIndex 2 1 NumberFormat mm ss 0 End Sub Function ConvertTime TimeString As String As Date This routine will take the string returned from the SYSTem TIME SCAN command and return a number compatib...

Страница 250: ...the VISA functionality and does not include error trapping Error trapping however is good programming practice and is recommended for your application For more information on error trapping refer to the Agilent VISA User s Guide The example programs are written in Microsoft Visual C Version 1 52 using project type QuickWin application and using the large memory model Be sure to have access in the ...

Страница 251: ...ule double voltage Value of voltage sent to DAC Build the address required to open communication with GPIB card The address format looks like this GPIB0 9 INSTR strcpy Visa_address GPIB0 strcat Visa_address ADDR strcat Visa_address INSTR Open communication session with the 34970A viOpenDefaultRM defaultRM viOpen defaultRM Visa_address VI_NULL VI_NULL dac Query the module id in slot 200 Read respon...

Страница 252: ...gisters to generate an interrupt whenever an alarm is detected on Alarm 1 or when the operation is complete viPrintf DataAcqu STATUS ALARM ENABLE 1 n Enable Alarm 1 viPrintf DataAcqu ESE 1 n Enable the Operation Complete bit Enable Status Byte Register bit 1 2 and 5 32 for SRQ viPrintf DataAcqu SRE 34 n Enable the interrupt handler for SRQ from the instrument viInstallHandler DataAcqu VI_EVENT_SER...

Страница 253: ...the controller with an SRQ for alarm and or Operation Complete ViStatus _VI_FUNCH SRQ_handler ViSession DataAcqu ViEventType eventType ViEvent context ViAddr userHdlr ViUInt16 statusByte viReadSTB DataAcqu statusByte Read status byte register and clear SRQ Bit 6 64 indicates this SRQ is for our instrument bit 1 2 indicates an alarm and bit 5 32 indicates the standard event register so alarm 64 2 6...

Страница 254: ...254 34970A Refresh UG book Page 254 Wednesday February 17 2010 12 34 PM ...

Страница 255: ...7 7 Tutorial 34970A Refresh UG book Page 255 Wednesday February 17 2010 12 34 PM ...

Страница 256: ...ts This chapter is divided into the following sections System Cabling and Connections on page 257 Measurement Fundamentals on page 265 Low Level Signal Multiplexing and Switching on page 300 Actuators and General Purpose Switching on page 306 Matrix Switching on page 310 RF Signal Multiplexing on page 312 Multifunction Module on page 314 Relay Life and Preventive Maintenance on page 321 34970A Ref...

Страница 257: ...ting Maintenance Requirements such as intermediate connectors cable terminations strain relief cable lengths and cable routing Cables are specified in a variety of ways Be sure to check the following specifications for the cable type you intend to use continued on the following page Nominal Impedance insulation resistance Varies with the frequency of the input signal Check for HI to LO channel to ...

Страница 258: ...nsulation type cable length and cable shielding Cables should be kept as short as possible to minimize cable capacitance In some cases low capacitance cable can be used The table below lists typical cable specifications AWG ft 2 conductors at 25 C 14 16 18 20 22 24 5 m 10 m 15 m 20 m 30 m 50 m Cable Type Nominal Impedance Capacitance Attenuation Twisted Pair 100 at 1 MHz 10 to 20 pF ft Up to 1 dB ...

Страница 259: ...ow level signals use single point grounding see below Parallel grounding is superior but is also more expensive and more difficult to wire If single point grounding is adequate the most critical points those with the lowest levels and or the most precise measurement requirements should be positioned near the primary ground point For frequencies above 10 MHz use the separate grounding system For si...

Страница 260: ...pair for immunity from magnetic and capacitive pickup For maximum protection below 1 MHz make sure that the shield is not one of the signal conductors Separation of High Level and Low Level Signals Signals whose levels exceed a 20 to 1 ratio should be physically separated as much as possible The entire signal path should be examined including cabling and adjacent connections All unused lines shoul...

Страница 261: ...ers computer monitors and cellular telephones High frequency energy can also be coupled to the internal DMM on the system cabling To reduce the interference try to minimize the exposure of the system cabling to high frequency RF sources If your application is extremely sensitive to RFI radiated from the instrument use a common mode choke in the system cabling as shown below to attenuate instrument...

Страница 262: ... can be induced by either movement of the input connection wiring in a fixed magnetic field or by a varying magnetic field An unshielded poorly dressed input wire moving in the earth s magnetic field can generate several millivolts The varying magnetic field around the AC power line can also induce voltages up to several hundred millivolts You should be especially careful when working near conduct...

Страница 263: ...tage VL which is added to the measured voltage Where RL Lead resistance Ri DMM isolation resistance Ci DMM isolation capacitance Vground Ground noise voltage I Current flow caused by Vground Z ZCi 10 M at 50 or 60 Hz VL To minimize ground loop errors If Vground is a DC voltage keep RL small compared to Ri If Vground is an AC voltage keep RL small compared to Z and set the DMM s integration time to...

Страница 264: ...ow impedance source You can reduce the high frequency impedance of a source by placing a capacitor in parallel with the instrument s input terminals You may have to experiment to determine the correct capacitance value for your application Most extraneous noise is not correlated with the input signal You can determine the error as shown below Voltage Measured Correlated noise while rare is especia...

Страница 265: ...og to digital converter A simplified diagram of the internal DMM is shown below For complete details on the operation of the internal DMM refer to Measurement Input on page 74 The internal DMM can directly make the following types of measurements Each of these measurements is described in the following sections of this chapter Temperature thermocouple RTD and thermistor Voltage dc and AC up to 300...

Страница 266: ...t measures the power line frequency 50 Hz or 60 Hz and uses this measurement to determine the integration time The table below shows the noise rejection achieved with various configurations For better resolution and increased noise rejection select a longer integration time The following graph shows the attenuation of AC signals measured in the DC voltage function for various A D integration time ...

Страница 267: ...t requirements will help you to determine which temperature transducer type to use Each transducer type has a particular temperature range accuracy and cost The table below summarizes some typical specifications for each transducer type Use this information to help select the transducer for your application The transducer manufacturers can provide you with exact specifications for a particular tra...

Страница 268: ...s using a 2 wire or 4 wire measurement method The 4 wire method provides the most accurate way to measure small resistances Connection lead resistance is automatically removed using the 4 wire method Thermistor Measurements A thermistor is constructed of materials that non linearly changes resistance with changes in temperature The internal DMM measures the resistance of the thermistor and then ca...

Страница 269: ...ht look like this Notice however that the connections made between the thermocouple wire and the internal DMM make a second unwanted thermocouple where the constantan C lead connects to the internal DMM s copper Cu input terminal The voltage generated by this second thermocouple affects the voltage measurement of the T type thermocouple If the temperature of the thermocouple created at J2 the LO i...

Страница 270: ...ermocouple is used two additional thermocouples are created For example take a look at the connections with a J type thermocouple iron and constantan Two additional thermocouples have been created where the iron Fe lead connects to the internal DMM s copper Cu input terminals Since these two junctions will generate opposing voltages their effect will be to cancel each other However if the input te...

Страница 271: ... Intermediate Metals eliminates the need for the extra connection This empirical law states that a third metal iron Fe in this example inserted between two dissimilar metals will have no effect upon the output voltage provided the junctions formed are at the same temperature Removing the reference thermocouple makes the connections much easier This circuit is the best solution for accurate thermoc...

Страница 272: ...known accurate temperature measurements can be made A temperature sensor is mounted to the isothermal block to measure its temperature Thermocouples are available in a variety of types The type is specified by a single letter The table on the following page shows the most commonly used thermocouple types and some key characteristics of each Note The thermocouple conversion routines used by the 349...

Страница 273: ... 8 C T U S British DIN Japanese French Copper Blue White Red Red Yellow Constantan Red Blue Brown White Blue 200 C 400 C 0 5 C 1 C Withstands moisture Has a copper lead Low temperature applications E U S British DIN Japanese French Nickel Chromium Purple Brown Red Red Yellow Constantan Red Blue Black White Blue 200 C 1000 C 1 C 1 7 C Highest output voltage Highest resolution N U S British DIN Japa...

Страница 274: ... the instrument measures the channel resistance after each thermocouple measurement to ensure a proper connection For more information on using the thermocouple check feature see page 124 Diffusion Error Diffusion in a thermocouple wire is the process of changing the alloy type along the wire itself Atmospheric particles can actually diffuse into the metal These changes in the wire alloy introduce...

Страница 275: ... through the internal DMM voltage errors are generated along the distributed resistance of the thermocouple wire Adding a shield to the thermocouple wire will shunt the common mode noise to earth ground and preserve the measurement Common mode noise can dramatically affect the internal DMM A typical thermocouple output is a few millivolts and a few millivolts of common mode noise can overload the ...

Страница 276: ...witch is closed and the signal is attenuated 100 1 before being applied to the input amplifier The input amplifier gain is set to one of three values x1 x10 or x100 to yield a signal in the range of 12 VDC for the analog to digital converter For the lower voltage ranges the internal DMM s input resistance is essentially that of the input amplifier The input amplifier uses a low bias current less t...

Страница 277: ...rop VL as shown below Any resulting voltage VL will appear as an input to the internal DMM As the value of RS approaches zero so does the error Additionally if Vf is at the power line frequency 50 Hz or 60 Hz the noise can be greatly reduced by setting the internal DMM s integration time to 1 PLC or greater see page 120 for a discussion of integration time Where Vf Common mode float voltage Rs LO ...

Страница 278: ...t flows from the earth connection provided by the circuit to the LO terminal of the internal DMM This configuration adds no noise to the measurement However with Connection B the injected current flows through the resistor R thus adding noise to the measurement With Connection B larger values of R will make the problem worse The measurement noise caused by injected current can be significantly red...

Страница 279: ...trument s own input resistance The diagram below shows this error source Where Vs Ideal DUT voltage Rs DUT source resistance Ri Input resistance 10 M or 10 G Error To minimize loading errors set the DMM s DC input resistance to greater than 10 G when needed for more information on DC input resistance see page 130 Rs DMM Ri HI LO Vs 100 Rs Rs Ri 34970A Refresh UG book Page 279 Wednesday February 17...

Страница 280: ...ut bias current is a loading error at the internal DMM s input terminals The leakage current will approximately double for every 10 C temperature rise thus making the problem much more apparent at higher temperatures Where Ib DMM bias current Rs DUT source resistance Ri Input resistance 10 M or 10 G Ci DMM input capacitance Error V Ib X Rs Vs DMM Rs HI LO Ri Ci Ib 34970A Refresh UG book Page 280 W...

Страница 281: ... amplifier and gain from the second stage amplifier The first stage implements a high input impedance 1 M switchable compensated attenuator The second stage provides variable gain signal amplification to scale the input to the AC converter to the full scale level Any residual DC offset from the attenuator and amplifier stages is blocked by a capacitor An AC voltage front end similar to the one dis...

Страница 282: ...e heating value of the AC component of the input waveform is measured dc is rejected For sinewaves triangle waves and square waves the AC and AC DC values are equal since these waveforms do not contain a DC offset Non symmetrical waveforms such as pulse trains contain DC voltages which are rejected by ac coupled true RMS measurements An ac coupled true RMS measurement is desirable in situations wh...

Страница 283: ...the fast filter 200 Hz will settle at 10 readings per second If the sample to sample levels are similar little settling time is required for each new reading Under this specialized condition the medium filter 20 Hz will provide reduced accuracy results at 5 readings per second and the fast filter 200 Hz will provide reduced accuracy results at 50 readings per second Additional settling time may be...

Страница 284: ...he duty cycle as shown in the table on page 360 In general the greater the crest factor the greater the energy contained in higher frequency harmonics All multimeters exhibit measurement errors that are crest factor dependent Crest factor errors are shown in the specifications in chapter 8 Note that the crest factor errors do not apply for input signals below 100 Hz when using the slow AC filter Y...

Страница 285: ...he internal DMM is set to the 1 V range For this example use the 90 day accuracy specifications of 0 05 of reading 0 04 of range as shown in chapter 8 Errorsine 0 05 0 04 0 09 Errorcrest factor 0 15 Errorbandwidth 100 1 4 Total Error 0 09 0 15 1 4 1 6 Example Calculating Measurement Error 3 2 20000 4 3 14159 1000000 34970A Refresh UG book Page 285 Wednesday February 17 2010 12 34 PM ...

Страница 286: ...he table below shows the approximate input resistance at various frequencies For low frequencies Error Additional error for high frequencies Error 100 x F Input frequency Rs Source resistance Cin Input capacitance 150 pF Cable capacitance Use low capacitance cable when measuring high frequency AC signals see page 258 Input Frequency Input Resistance 100 Hz 1 kHz 10 kHz 100 kHz 700 k 600 k 100 k 10...

Страница 287: ...w impedance source You can reduce the high frequency impedance of a source by placing a capacitor in parallel with the instrument s input terminals You may have to experiment to determine the correct capacitance value for your application Most extraneous noise is not correlated with the input signal You can determine the error as shown below Voltage Measured Correlated noise while rare is especial...

Страница 288: ...ccuracy you should use manual ranging to select the lowest range possible for the measurement Temperature Coefficient and Overload Errors The internal DMM uses an AC measurement technique that periodically measures and removes internal offset voltages when you select a different function or range When manual ranging to a new range in an overload condition the internal offset measurement may be deg...

Страница 289: ... burden voltage or IR drop This voltage drop is sensed by the internal DMM and scaled to the proper current value to complete the measurement see the discussion on the following page AC current measurements are very similar to DC current measurements The output of the current to voltage sensor is measured by an AC voltmeter The input terminals are direct coupled ac dc coupled to the shunt so that ...

Страница 290: ...istance Vb Burden voltage R Current shunt resistance Error Sources of Error in AC Current Measurements Burden voltage errors which apply to DC current also apply to AC current measurements However the burden voltage for AC current is larger due to the internal DMM s series inductance and the measurement connections The burden voltage increases as the input frequency increases Some circuits may osc...

Страница 291: ...flows in the sense leads the resistance in these leads does not give a measurement error 4 Wire Ohms Measurements The 4 wire ohms method provides the most accurate way to measure small resistances Test lead multiplexer and contact resistances are automatically reduced using this method The 4 wire ohms method is often used in automated test applications where long cable lengths input connections an...

Страница 292: ...he obvious disadvantage of requiring twice as many switches and twice as many wires as the 2 wire method The 4 wire ohms method is used almost exclusively for measuring lower resistance values in any application especially for values less than 10 and for high accuracy requirements such as RTD temperature transducers HI Sense Vmeter Itest LO Source HI Source R Vmeter Itest LO Sense 34970A Refresh U...

Страница 293: ...ing the result thus giving a more accurate resistance measurement Refer to Offset Compensation on page 132 for more information Offset compensation can be used for 2 wire or 4 wire ohms measurements but not for RTD or thermistor measurements The 34970A 34972A disables offset compensation when the measurement function is changed or after a Factory Reset RST command An Instrument Preset SYSTem PRESe...

Страница 294: ...tants Errors will be measured when settling after the initial connection after a range change or when using offset compensation You may need to increase the channel delay time before a measurement in these situations for more information on channel delay see page 105 High Resistance Measurement Errors When you are measuring large resistances significant errors can occur due to insulation resistanc...

Страница 295: ...ormal Strain is a measure of the deformation along the axis of the applied force L L Shearing Strain is a measure of the angular distortion of a body It is approximated by the tangent of the angle formed by the angular change between two line segments that were parallel in the undeformed state Poisson Strain measures a property of materials known as the Poisson Ratio It is the negative ratio of tr...

Страница 296: ...arious numbers and configurations of elements The most common element is the single gage form shown below Multi element strain gages also called rosettes are used to measure components of strain in different directions Two element 90 and three element 45 or 60 configurations are the most common Common Uses for Strain Gages Strain gages are used to sense many types of physical parameters Strain gag...

Страница 297: ...e Mx B scaling function with the equations shown below will allow you to display results directly in strain on the 34970A 34972A front panel display You can use a custom measurement label to display readings in micro strain directly The instrument will automatically add the micro prefix based upon actual calculated values For more information on scaling see page 136 M B Temperature Effects The res...

Страница 298: ...tched and the result is divided by the known timebase frequency to determine the input frequency The counter is then reset before the next gate period The resolution of the measurement is tied to the timebase and not the input frequency This increases measurement speed especially at low frequencies The reciprocal counter has the advantage of a constant number of digits of display no matter what th...

Страница 299: ...to frequency Measurement errors will also occur if you attempt to measure the frequency or period of an input following a DC offset voltage change You must allow the internal DMM s input DC blocking capacitor to fully settle before making frequency measurements If the external noise pickup becomes large enough to exceed the hysteresis of the measuring circuitry the frequency function may actually ...

Страница 300: ...plexer An important feature of a multiplexer used as a DMM input channel is that only one channel is connected at a time For example using a multiplexer module and the internal DMM you could configure a voltage measurement on channel 1 and a temperature measurement on channel 2 The instrument first closes the channel 1 relay makes the voltage measurement and then opens the relay before moving on t...

Страница 301: ...losed channel Two Wire Multiplexers The 34901A and 34902A multiplexers switch both HI and LO inputs thus providing fully isolated inputs to the internal DMM or an external instrument These modules also provide a thermocouple reference junction for making thermocouple measurements for more information on the purpose of an isothermal block see page 272 Note If any channels are configured to be part ...

Страница 302: ...terminals on channel 2 and the sense connections to the HI and LO terminals on channel 12 Note If any channels are configured to be part of the scan list you cannot close multiple channels closing one channel will open the previously closed channel When making a 4 wire measurement the test current flows through the source connections from the HI terminal through the resistor being measured To elim...

Страница 303: ...sed at the same time You must be careful that this does not create a hazardous condition for example connecting two power sources together Note that a multiplexer is not directional For example you can use a multiplexer with a source such as a DAC to connect a single source to multiple test points as shown below Channel 1 Channel 2 Channel 3 Channel 4 DAC OUT GND COM H COM L Multiplexer 34970A Ref...

Страница 304: ...nt channels in a switching system Noise can be coupled between the switch contacts themselves Csw or between adjacent cabling Cadj Capacitive noise coupling is a function of area and proximity A simple method to reduce the noise coupling is to physically separate the switches and cables from each other However this may not be practical for all applications Another solution is to keep large amplitu...

Страница 305: ... all of the channels on the multiplexer divide the input signals equally between Bank 1 and Bank 2 For example if you are multiplexing eight channels using the 16 channel multiplexer use four channels in the lower bank and four channels in the upper bank For even better noise immunity leave one unused grounded channel between each input channel Module Bank 1 Bank 2 34901A Channels 1 through 10 Cha...

Страница 306: ...n use an actuator to build a simple resistance ladder as shown below In the above diagram the resistance is 60 when all of the actuator channels are open not connected to COM Note that when the actuator channels are open as shown above the normally closed contacts not shown above are connected to COM Values from 10 to 50 are selected by closing the appropriate channel s on the module COM COM COM C...

Страница 307: ...ere You can build these networks to provide contact protection when actuating AC power line for reactive loads Although many types of contact protection networks can be used only RC networks and varistors are described in this section RC Protection Networks When designing RC protection networks the protection resistor Rp is selected as a compromise between two resistance values The minimum value o...

Страница 308: ...owable circuit capacitance is where L is the inductance of the load and Io is the current value calculated earlier The total circuit capacitance C is actually made up of the wiring capacitance plus the value of the protection network capacitor Cp Therefore the minimum value for Cp should be the value obtained for the total circuit capacitance C Note that the actual value used for Cp should be subs...

Страница 309: ...own below To select the attenuator components use the following equation One typical use for the shunt component is with 4 to 20 mA transducers A 50 1 0 5 watt resistor can be installed in the R2 location The resultant voltage drop transducer current through the resistor can be measured by the internal DMM Thus the 50 resistor converts the 4 to 20 mA current to a 0 2 to 1 volt signal R1 R2 Vsignal...

Страница 310: ...s For example a simple 3x3 matrix could be used to connect three sources to three test points as shown below Any one of the signal sources can be connected to any one of the test inputs Be aware that with a matrix it is possible to connect more than one source at the same time It is important to make sure that dangerous or unwanted conditions are not created by these connections Source 1 Source 2 ...

Страница 311: ...ple the 34904A provides a 4 row by 8 column matrix You can combine two of these modules as either a 4 row by 16 column matrix or an 8 row by 8 column matrix An 8x8 matrix is shown below 8 Rows Row 1 Row 4 Row 1 Row 4 Col 1 Col 8 Col 1 Col 8 8 Columns Matrix Module 1 Matrix Module 2 34970A Refresh UG book Page 311 Wednesday February 17 2010 12 34 PM ...

Страница 312: ...ide additional test inputs or outputs For example you can combine two 4 to 1 multiplexers to create a 7 to 1 multiplexer as shown below On the 34905A 50 and 34906A 75 RF multiplexers you can close only one channel per bank at a time closing one channel in a bank will open the previously closed channel These modules respond only to the CLOSE command OPEN does not apply To open a channel send the CL...

Страница 313: ...onnector for the circuit impedance 50 or 75 Note that it is difficult to visually differentiate a 50 connector from a 75 connector Be sure that all leads and signal paths are properly terminated Unterminated sections of line can appear as near shorts at RF frequencies Note that the 34905A and 34906A do not automatically terminate open channels Insertion Loss 75 Insertion Loss 50 VSWR 50 VSWR 75 Di...

Страница 314: ... bit pattern change is detected on an input channel The channels do not have to be part of the scan list to generate an alarm The internal 5V pull up circuitry allows you to use the digital input to detect contact closures like micro switches or limit switches An open input floats to 5V and is read as a 1 An input shorted to ground is read as a 0 An example of a contact closure detection channel i...

Страница 315: ...rom the internal 5V supply through the diode The drive is rated at 2 4V minimum at 1 mA Each output bit is also an active sink capable of sinking up to 400 mA from an external power supply The FET is used to sink currents and has a nominal on resistance of 0 2 For non TTL logic you must provide an external pull up A description of the pull up calculation is given on the following page If used with...

Страница 316: ... 24 k pull up resistor is calculated as follows Vhigh Vcc x 12 x 8 47 VDC Driving External Switches You can use two digital output channels to control an external switch For example you can drive the Agilent 876X series of microwave switches using an external power supply and two digital output channels The state of the 2 to 1 multiplexer is changed by setting the appropriate output bit low 0 Vcc ...

Страница 317: ...odule you can control the threshold at which an edge is detected Move the jumper to the AC position to detect changes through 0 volts Move the jumper to the TTL position factory setting to detect changes through TTL threshold levels The maximum count is 67 108 863 226 1 The count rolls over to 0 after reaching the maximum allowed value Signal Conditioning Threshold Jumper _ G GND Totalizer On Off ...

Страница 318: ...inal floats to the enabled state effectively creating a gate always condition Totalizer Errors Noise on the totalizer input can be a problem especially on signals with a slow rise time This noise can create a false indication of a threshold crossing For more information on cabling noise see page 257 Contact bounce on external switches can create false counts All mechanical switches bounce when the...

Страница 319: ...ther devices You can set the output voltage to any value between 12 VDC and 12 VDC in 1 mV steps Each DAC is earth referenced it cannot float Each DAC channel is capable of supplying 10 mA maximum current Note You must limit the output current to 40 mA total for all three slots six DAC channels To maintain the rated output accuracy the load RL in the diagram shown above must be greater than 1 k 16...

Страница 320: ...tial error and integral error Differential Error refers to the smallest possible change in voltage The DAC output is not linear but is stepped as progressively larger or smaller voltages are programmed The step size is 1 mV Integral Error refers to the difference between the programmed voltage and the actual output voltage from the DAC This error is included in the output specifications shown in c...

Страница 321: ...of relay wear out mechanisms In general relay lifetimes depend heavily upon the signals that are being switched and the types of measurements being performed Switching typical signal levels will result in relay lifetimes from 1 000 000 to 10 000 000 operations High power switching 25 rating or high voltage switching 100V applications will yield relay lifetimes from 100 000 to 1 000 000 operations ...

Страница 322: ...l contact resistance characteristics of the relays used on the 34970A 34972A switching modules Relay Load For most applications the load switched by the relay is the most important factor affecting relay life As shown in the graph below relay life is maximized by switching low power As the power switched increases relay life deteriorates 1k 10k 100k 1M 10M 100M 0 1 Typical Relay Lifetime Relay Ope...

Страница 323: ...becomes erratic This is suitable if you are switching higher loads on only a few relays on the module The disadvantage of this strategy is the inconvenience of continually replacing relays as they near the end of their life at different times The second strategy is to replace all relays on the module or simply purchase a new module as the relays near the end of their life This strategy is best sui...

Страница 324: ...324 34970A Refresh UG book Page 324 Wednesday February 17 2010 12 34 PM ...

Страница 325: ...ns 1 on page 331 Module Specifications 34901A 34902A 34908A 34903A 34904A on page 333 Module Specifications 34905A 34906A on page 334 Typical AC Performance Graphs 34905A 34906A on page 335 Module Specifications 34907A on page 336 Product and Module Dimensions on page 337 To Calculate Total Measurement Error on page 338 Interpreting Internal DMM Specifications on page 340 Configuring for Highest A...

Страница 326: ...0 0000 1 000000 k 10 00000 k 100 0000 k 1 000000 M 10 00000 M 100 0000 M 1 mA current source 1 mA 100 A 10 A 5 A 500 nA 500nA 10 M 0 0030 0 0035 0 0020 0 0006 0 0020 0 0005 0 0020 0 0005 0 002 0 001 0 015 0 001 0 300 0 010 0 008 0 004 0 008 0 001 0 008 0 001 0 008 0 001 0 008 0 001 0 020 0 001 0 800 0 010 0 010 0 004 0 010 0 001 0 010 0 001 0 010 0 001 0 010 0 001 0 040 0 001 0 800 0 010 0 0006 0 ...

Страница 327: ...anges 10 of range per lead for 100 and 1 k ranges 1 k on all other ranges 300 V on all ranges DC Current Shunt Resistance Input Protection 5 for 10 mA 100 mA 0 1 for 1A 1 5A 250 V fuse on 34901A module Thermocouple Conversion Reference Junction Type Open T C Check ITS 90 software compensation Internal Fixed or External Selectable per channel Open 5 k RTD 0 00385 DIN IEC 751 using ITS 90 software c...

Страница 328: ...kHz 50 kHz 50 kHz 100 kHz 100 kHz 300 kHz 5 1 00 0 05 0 35 0 05 0 04 0 05 0 10 0 10 0 55 0 20 4 00 1 25 1 00 0 08 0 35 0 08 0 05 0 08 0 11 0 12 0 60 0 20 4 00 1 25 1 00 0 08 0 35 0 08 0 06 0 08 0 12 0 12 0 60 0 20 4 00 1 25 0 100 0 008 0 035 0 008 0 005 0 008 0 011 0 012 0 060 0 020 0 20 0 05 Frequency and Period 6 100 mV to 300 V 3 Hz 5 Hz 5 Hz 10 Hz 10 Hz 40 Hz 40 Hz 300 kHz 0 10 0 05 0 03 0 006...

Страница 329: ...n parallel with 150 pF 300 Vrms on all ranges Frequency and Period Measurement Method Voltage Ranges Gate Time Measurement Timeout Reciprocal counting technique Same as AC Voltage function 1s 100 ms or 10 ms Selectable 3 Hz 20 Hz 200 Hz LF limit True RMS AC Current Measurement Method Shunt Resistance Input Protection Direct coupled to the fuse and shunt AC coupled True RMS measurement measures the...

Страница 330: ...ypical life 1 34972A User replaceable battery recommended replacement during yearly calibration 50 000 internal readings with timestamp readable during scan 1 ms 1 s 5 instrument states Up to 20 events FAT or FAT32 format General Specifications Power Supply Power Line Frequency Power Consumption Operating Environment Storage Environment Weight Mainframe Safety RFI and ESD Warranty 100 V 120 V 220 ...

Страница 331: ...changing function eg MEAS dcV MEAS Ohms 12 12 12 Scanning Measurement Rates to I O or internal memory 34970A 34972A into Memory to GPIB or RS232 to LAN USB or Memory ch sec ch sec ch sec Scanning DCV or Ohms channels 34901A 34908A 60 60 60 34902A 250 210 240 34902A into and out of memory using INIT FETCh 180 240 34902A with timestamp using MEAS 150 240 34902A with scaling and alarms 220 190 220 34...

Страница 332: ...onnection VXI11 will be less 5 For fixed function and range readings to memory scaling alarms autozero off Data out of memory 3 4 34970A 34972A FETCh of 50K readings over GPIB over RS232 over USB over LAN or memory readings sec readings sec readings sec readings sec Readings 800 600 55K 120K Readings with timestamp 450 320 35K 60K Readings with all format options ON 310 230 25K 50K 34970A Refresh ...

Страница 333: ... s 120 s 70 s 120 s 120 s Maximum Input Voltage dc AC rms 300 V 300 V 300 V 300 V 300 V Current dc AC rms 1 A 50 mA 1 A 1 A 1 A Power W VA 50 W 2 W 50W 50W 50W Isolation ch ch ch earth dc AC rms 300 V 300 V 300 V 300 V 300 V DC Characteristics Offset Voltage 2 3 V 6 V 3 V 3 V 3 V Initial Closed Channel R 2 1 1 1 0 2 1 Isolation ch ch ch earth 10 G 10 G 10 G 10 G 10 G AC Characteristics Bandwidth 1...

Страница 334: ...ltage dc AC rms 42 V Current dc AC rms 0 7 A Power W VA 20 W DC Characteristics Offset Voltage 1 6 V Initial Closed Channel R 1 0 5 Isolation ch ch ch earth 1 G Other Switch Life No Load typical 5M Switch Life Rated Load typical 2 100k Temperature Operating 0 C to 55 C Temperature Storage 20 C to 70 C Humidity non condensing 40 C 80 R H 34970A Refresh UG book Page 334 Wednesday February 17 2010 12...

Страница 335: ...ce Graphs 4 8 Typical AC Performance Graphs 34905A 34906A Insertion Loss 75 Insertion Loss 50 VSWR 50 VSWR 75 Direct to Module Using provided adapter cables Crosstalk 50 Crosstalk 75 34970A Refresh UG book Page 335 Wednesday February 17 2010 12 34 PM ...

Страница 336: ...s max alarm sampling 5 ms typical to 34970A 34972A alarm output 95 s Totalize Input Maximum Count Totalize Input Signal Level Threshold Gate Input County Reset Read Speed 226 1 67 108 863 100 kHz max rising or falling edge programmable 1 Vp p min 42 Vpk max 0V or TTL jumper selectable TTL HI TTL LO or none Manual or Read Reset 85 s Analog Voltage DAC Output DAC 1 2 Resolution Iout Settling Time Ac...

Страница 337: ...and Module Dimensions 4 8 Product and Module Dimensions 103 6 mm 374 0 mm 254 4 mm 212 6 mm 88 5 mm 348 3 mm Module TOP 315 6 91 9 All dimensions are shown in millimeters 34970A Refresh UG book Page 337 Wednesday February 17 2010 12 34 PM ...

Страница 338: ...ions as described in the footnotes on the specification pages If you are operating the internal DMM outside the 23 C 5 C temperature range specified apply an additional temperature coefficient error For DC voltage DC current and resistance measurements you may need to apply an additional reading speed error For AC voltage and AC current measurements you may need to apply an additional low frequenc...

Страница 339: ...nt of input error or a ppm part per million of input error as shown below of input error x 100 ppm of input error x 1 000 000 Assume that a 5 VDC signal is input to the DMM on the 10 VDC range Compute the total measurement error using the 90 day accuracy specification of 0 0020 of reading 0 0005 of range Range Input Level Reading Error of reading Range Error Voltage 10 VDC 10 VDC 10 VDC 10 VDC 1 V...

Страница 340: ...imum of 12 00000 VDC This corresponds to a 6 digit measurement with 20 overrange capability Sensitivity Sensitivity is the minimum level that the internal DMM can detect for a given measurement Sensitivity defines the ability of the internal DMM to respond to small changes in the input level For example suppose you are monitoring a 1 mVDC signal and you want to adjust the level to within 1 µV To b...

Страница 341: ... relative to national standards such as the U S National Institute of Standards and Technology To be meaningful the accuracy specifications must be accompanied with the conditions under which they are valid These conditions should include temperature humidity and time There is no standard convention among instrument manufacturers for the confidence limits at which specifications are set The table ...

Страница 342: ...g term accuracy specifications are valid for a 23 C 5 C temperature range These specifications include the initial calibration errors plus the internal DMM s long term drift errors Temperature Coefficients Accuracy is usually specified for a 23 C 5 C temperature range This is a common temperature range for many operating environments You must add additional temperature coefficient errors to the ac...

Страница 343: ...stance Measurements Set the resolution to 6 digits you can use the 6 digits slow mode for further noise reduction Set the input resistance to greater than 10 G for the 100 mV 1 V and 10 V ranges for the best DC voltage accuracy Use 4 wire ohms and enable offset compensation for the best resistance accuracy AC Voltage and AC Current Measurements Set the resolution to 6 digits Select the slow AC fil...

Страница 344: ...344 Chapter 8 Specifications Configuring for Highest Accuracy Measurements 34970A Refresh UG book Page 344 Wednesday February 17 2010 12 34 PM ...

Страница 345: ...nary format 49 151 channel numbering 210 clearing the count totalizer 156 current limitations DAC 159 317 decimal format 49 151 description 210 driving microwave switches 314 gate signal 153 maximum totalizer count 154 module overview 14 210 screw terminal diagram 211 simplified block diagrams 210 Totalize Threshold jumper 154 211 totalizer reset mode 155 using alarms 148 wiring log 211 34908A mod...

Страница 346: ...emory 143 while scanning 92 with multifunction module 148 Alarms connector 145 alpha a for RTDs default 127 values 127 analog to digital conversion explanation 76 integrating technique 76 non integrating technique 76 annunciators 8 141 aperture time definition 120 selecting 120 application programs C and C 248 Excel 7 0 241 242 attenuation 256 264 307 automatic channel delays 106 Automatic Logging...

Страница 347: ... 95 examples 89 rules 89 channel number with readings 104 channel numbering 30 34901A 200 34902A 202 34903A 204 34904A 206 34905A 208 34906A 208 34907A 210 34908A 212 chassis ground 9 10 clearing reading memory 91 clock factory setting 166 setting the 29 166 Close key 33 coaxial cables 67 258 coefficient temperature 286 color codes thermocouples 271 command syntax SCPI conventions 89 version query...

Страница 348: ...tioning 274 decimal format digital input 49 151 default delays channel delays 106 Default Gateway 190 delay channel delay 105 DHCP 188 dielectric withstand voltage 255 differential error DAC 318 diffusion error 272 digital channels external scan ning 113 digital input 34907A 8 bit vs 16 bit operations 151 adding to scan list 49 151 binary format 49 151 block diagram 210 card reset 151 152 decimal ...

Страница 349: ...odem mode 186 None no flow mode 185 RTS CTS mode 185 selecting 54 185 XON XOFF mode 185 form C SPDT switching 73 304 format alarm queue data 144 scanned readings 104 four wire multiplexers 71 300 four wire ohms 132 289 four wiring paring RTD 127 frequency measurements connections 28 low frequency timeout 135 sources of error 297 front panel annunciators 8 defining scan list 30 layout 6 menu overvi...

Страница 350: ...abling disabling 167 reading relay count 169 internal reference thermocouple 124 internal timer scan interval 124 Interval key 42 97 113 interval scan default value 97 resolution 97 setting from front panel 97 setting from remote 97 settings 97 interval scan to scan 45 96 IP address 189 IPTS 68 conversions 127 266 isothermal block 124 270 ITS 90 conversions 127 266 J jumper Totalize Threshold 154 ...

Страница 351: ...count 169 Mon key 44 172 MON annunciator 8 Monitor function definition 171 scan on alarm 101 172 while scanning 91 with alarms 171 with Mx B scaling 171 multiplexer types 298 multiplexers errors 301 four wire 71 300 one wire single ended 71 298 two wire 71 298 VHF 71 Mx B key 41 46 Mx B scaling custom label 46 137 default gain M 136 138 default offset B 136 138 equation used 136 interaction with a...

Страница 352: ...interference 259 random noise 297 range autorange 115 overload 115 selecting 116 ranges by function 2 wire ohms 28 132 4 wire ohms 28 132 ac current 28 133 ac voltage 28 130 dc current 28 133 dc voltage 28 130 RC protection circuitry 305 Read key 49 51 READ command 95 reading format 104 readings memory storing alarms 139 readings viewing 31 107 real time clock factory setting 166 setting 29 166 re...

Страница 353: ... interaction with alarms 136 null stored as offset 136 setting gain M 46 138 setting offset B 46 138 strain measurements 295 valid gain M values 137 valid offset B values 137 while scanning 91 136 SCAN annunciator 8 scan configuration copying 32 scan configuration front panel 30 scan count continuous 45 102 default value 45 102 settings 45 102 scan interval default value 45 97 resolution 97 settin...

Страница 354: ... 76 ac voltage 279 dc voltage 274 simplified schematic 34901A 200 34902A 202 34903A 204 34904A 206 34905A 208 34906A 208 34907A 210 34908A 212 single channel Monitor 171 172 sink current digital output 313 sliding shelf kit rack mounting 38 slope alarm output lines 146 slot numbering 9 10 slow ac filter 131 281 slow timeout 135 SMB cable kits 209 snubber circuitry 305 software BenchLink Data Logge...

Страница 355: ...easurement tutorial 267 measurement units 123 metals used 271 probe accuracy 271 reference junction error 272 reference junction 124 shielding 273 shunt impedance 273 temperature range 271 Thermocouple Check 125 types supported 28 thermoelectric voltages 260 threshold totalize 154 156 time clock factory setting 166 setting the 29 166 time stamp absolute 104 relative 104 timeout low frequency 135 t...

Страница 356: ...esetting 52 simplified schematic 317 writing 52 voltage dividers 305 voltage measurements 130 ac low frequency filter 131 ac settling time 131 VSWR 311 W Warnings 34901A 201 34902A 203 34903A 205 34904A 207 34908A 212 warranty 2 waveform tutorial 253 Wheatstone bridge strain 295 wire size gauge 256 wiring connections ac current 28 ac voltage 28 dc current 28 dc voltage 28 frequency 28 period 28 re...

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